1 /* Low level interface to ptrace, for the remote server for GDB.
2 Copyright (C) 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
3 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
21 #include "linux-low.h"
25 #include <sys/param.h>
26 #include <sys/ptrace.h>
28 #include <sys/ioctl.h>
34 #include <sys/syscall.h>
38 #include <sys/types.h>
44 /* Don't include <linux/elf.h> here. If it got included by gdb_proc_service.h
45 then ELFMAG0 will have been defined. If it didn't get included by
46 gdb_proc_service.h then including it will likely introduce a duplicate
47 definition of elf_fpregset_t. */
52 #define SPUFS_MAGIC 0x23c9b64e
55 #ifndef PTRACE_GETSIGINFO
56 # define PTRACE_GETSIGINFO 0x4202
57 # define PTRACE_SETSIGINFO 0x4203
64 /* If the system headers did not provide the constants, hard-code the normal
66 #ifndef PTRACE_EVENT_FORK
68 #define PTRACE_SETOPTIONS 0x4200
69 #define PTRACE_GETEVENTMSG 0x4201
71 /* options set using PTRACE_SETOPTIONS */
72 #define PTRACE_O_TRACESYSGOOD 0x00000001
73 #define PTRACE_O_TRACEFORK 0x00000002
74 #define PTRACE_O_TRACEVFORK 0x00000004
75 #define PTRACE_O_TRACECLONE 0x00000008
76 #define PTRACE_O_TRACEEXEC 0x00000010
77 #define PTRACE_O_TRACEVFORKDONE 0x00000020
78 #define PTRACE_O_TRACEEXIT 0x00000040
80 /* Wait extended result codes for the above trace options. */
81 #define PTRACE_EVENT_FORK 1
82 #define PTRACE_EVENT_VFORK 2
83 #define PTRACE_EVENT_CLONE 3
84 #define PTRACE_EVENT_EXEC 4
85 #define PTRACE_EVENT_VFORK_DONE 5
86 #define PTRACE_EVENT_EXIT 6
88 #endif /* PTRACE_EVENT_FORK */
90 /* We can't always assume that this flag is available, but all systems
91 with the ptrace event handlers also have __WALL, so it's safe to use
94 #define __WALL 0x40000000 /* Wait for any child. */
98 #define W_STOPCODE(sig) ((sig) << 8 | 0x7f)
102 #if !(defined(__UCLIBC_HAS_MMU__) || defined(__ARCH_HAS_MMU__))
107 /* ``all_threads'' is keyed by the LWP ID, which we use as the GDB protocol
108 representation of the thread ID.
110 ``all_lwps'' is keyed by the process ID - which on Linux is (presently)
111 the same as the LWP ID.
113 ``all_processes'' is keyed by the "overall process ID", which
114 GNU/Linux calls tgid, "thread group ID". */
116 struct inferior_list all_lwps
;
118 /* A list of all unknown processes which receive stop signals. Some other
119 process will presumably claim each of these as forked children
122 struct inferior_list stopped_pids
;
124 /* FIXME this is a bit of a hack, and could be removed. */
125 int stopping_threads
;
127 /* FIXME make into a target method? */
128 int using_threads
= 1;
130 /* This flag is true iff we've just created or attached to our first
131 inferior but it has not stopped yet. As soon as it does, we need
132 to call the low target's arch_setup callback. Doing this only on
133 the first inferior avoids reinializing the architecture on every
134 inferior, and avoids messing with the register caches of the
135 already running inferiors. NOTE: this assumes all inferiors under
136 control of gdbserver have the same architecture. */
137 static int new_inferior
;
139 static void linux_resume_one_lwp (struct lwp_info
*lwp
,
140 int step
, int signal
, siginfo_t
*info
);
141 static void linux_resume (struct thread_resume
*resume_info
, size_t n
);
142 static void stop_all_lwps (void);
143 static int linux_wait_for_event (ptid_t ptid
, int *wstat
, int options
);
144 static void *add_lwp (ptid_t ptid
);
145 static int linux_stopped_by_watchpoint (void);
146 static void mark_lwp_dead (struct lwp_info
*lwp
, int wstat
);
147 static int linux_core_of_thread (ptid_t ptid
);
148 static void proceed_all_lwps (void);
149 static void unstop_all_lwps (struct lwp_info
*except
);
150 static int finish_step_over (struct lwp_info
*lwp
);
151 static CORE_ADDR
get_stop_pc (struct lwp_info
*lwp
);
152 static int kill_lwp (unsigned long lwpid
, int signo
);
154 /* True if the low target can hardware single-step. Such targets
155 don't need a BREAKPOINT_REINSERT_ADDR callback. */
158 can_hardware_single_step (void)
160 return (the_low_target
.breakpoint_reinsert_addr
== NULL
);
163 /* True if the low target supports memory breakpoints. If so, we'll
164 have a GET_PC implementation. */
167 supports_breakpoints (void)
169 return (the_low_target
.get_pc
!= NULL
);
172 struct pending_signals
176 struct pending_signals
*prev
;
179 #define PTRACE_ARG3_TYPE void *
180 #define PTRACE_ARG4_TYPE void *
181 #define PTRACE_XFER_TYPE long
183 #ifdef HAVE_LINUX_REGSETS
184 static char *disabled_regsets
;
185 static int num_regsets
;
188 /* The read/write ends of the pipe registered as waitable file in the
190 static int linux_event_pipe
[2] = { -1, -1 };
192 /* True if we're currently in async mode. */
193 #define target_is_async_p() (linux_event_pipe[0] != -1)
195 static void send_sigstop (struct inferior_list_entry
*entry
);
196 static void wait_for_sigstop (struct inferior_list_entry
*entry
);
198 /* Accepts an integer PID; Returns a string representing a file that
199 can be opened to get info for the child process.
200 Space for the result is malloc'd, caller must free. */
203 linux_child_pid_to_exec_file (int pid
)
207 name1
= xmalloc (MAXPATHLEN
);
208 name2
= xmalloc (MAXPATHLEN
);
209 memset (name2
, 0, MAXPATHLEN
);
211 sprintf (name1
, "/proc/%d/exe", pid
);
212 if (readlink (name1
, name2
, MAXPATHLEN
) > 0)
224 /* Return non-zero if HEADER is a 64-bit ELF file. */
227 elf_64_header_p (const Elf64_Ehdr
*header
)
229 return (header
->e_ident
[EI_MAG0
] == ELFMAG0
230 && header
->e_ident
[EI_MAG1
] == ELFMAG1
231 && header
->e_ident
[EI_MAG2
] == ELFMAG2
232 && header
->e_ident
[EI_MAG3
] == ELFMAG3
233 && header
->e_ident
[EI_CLASS
] == ELFCLASS64
);
236 /* Return non-zero if FILE is a 64-bit ELF file,
237 zero if the file is not a 64-bit ELF file,
238 and -1 if the file is not accessible or doesn't exist. */
241 elf_64_file_p (const char *file
)
246 fd
= open (file
, O_RDONLY
);
250 if (read (fd
, &header
, sizeof (header
)) != sizeof (header
))
257 return elf_64_header_p (&header
);
261 delete_lwp (struct lwp_info
*lwp
)
263 remove_thread (get_lwp_thread (lwp
));
264 remove_inferior (&all_lwps
, &lwp
->head
);
265 free (lwp
->arch_private
);
269 /* Add a process to the common process list, and set its private
272 static struct process_info
*
273 linux_add_process (int pid
, int attached
)
275 struct process_info
*proc
;
277 /* Is this the first process? If so, then set the arch. */
278 if (all_processes
.head
== NULL
)
281 proc
= add_process (pid
, attached
);
282 proc
->private = xcalloc (1, sizeof (*proc
->private));
284 if (the_low_target
.new_process
!= NULL
)
285 proc
->private->arch_private
= the_low_target
.new_process ();
290 /* Remove a process from the common process list,
291 also freeing all private data. */
294 linux_remove_process (struct process_info
*process
)
296 struct process_info_private
*priv
= process
->private;
298 free (priv
->arch_private
);
300 remove_process (process
);
303 /* Wrapper function for waitpid which handles EINTR, and emulates
304 __WALL for systems where that is not available. */
307 my_waitpid (int pid
, int *status
, int flags
)
312 fprintf (stderr
, "my_waitpid (%d, 0x%x)\n", pid
, flags
);
316 sigset_t block_mask
, org_mask
, wake_mask
;
319 wnohang
= (flags
& WNOHANG
) != 0;
320 flags
&= ~(__WALL
| __WCLONE
);
323 /* Block all signals while here. This avoids knowing about
324 LinuxThread's signals. */
325 sigfillset (&block_mask
);
326 sigprocmask (SIG_BLOCK
, &block_mask
, &org_mask
);
328 /* ... except during the sigsuspend below. */
329 sigemptyset (&wake_mask
);
333 /* Since all signals are blocked, there's no need to check
335 ret
= waitpid (pid
, status
, flags
);
338 if (ret
== -1 && out_errno
!= ECHILD
)
343 if (flags
& __WCLONE
)
345 /* We've tried both flavors now. If WNOHANG is set,
346 there's nothing else to do, just bail out. */
351 fprintf (stderr
, "blocking\n");
353 /* Block waiting for signals. */
354 sigsuspend (&wake_mask
);
360 sigprocmask (SIG_SETMASK
, &org_mask
, NULL
);
365 ret
= waitpid (pid
, status
, flags
);
366 while (ret
== -1 && errno
== EINTR
);
371 fprintf (stderr
, "my_waitpid (%d, 0x%x): status(%x), %d\n",
372 pid
, flags
, status
? *status
: -1, ret
);
378 /* Handle a GNU/Linux extended wait response. If we see a clone
379 event, we need to add the new LWP to our list (and not report the
380 trap to higher layers). */
383 handle_extended_wait (struct lwp_info
*event_child
, int wstat
)
385 int event
= wstat
>> 16;
386 struct lwp_info
*new_lwp
;
388 if (event
== PTRACE_EVENT_CLONE
)
391 unsigned long new_pid
;
392 int ret
, status
= W_STOPCODE (SIGSTOP
);
394 ptrace (PTRACE_GETEVENTMSG
, lwpid_of (event_child
), 0, &new_pid
);
396 /* If we haven't already seen the new PID stop, wait for it now. */
397 if (! pull_pid_from_list (&stopped_pids
, new_pid
))
399 /* The new child has a pending SIGSTOP. We can't affect it until it
400 hits the SIGSTOP, but we're already attached. */
402 ret
= my_waitpid (new_pid
, &status
, __WALL
);
405 perror_with_name ("waiting for new child");
406 else if (ret
!= new_pid
)
407 warning ("wait returned unexpected PID %d", ret
);
408 else if (!WIFSTOPPED (status
))
409 warning ("wait returned unexpected status 0x%x", status
);
412 ptrace (PTRACE_SETOPTIONS
, new_pid
, 0, (PTRACE_ARG4_TYPE
) PTRACE_O_TRACECLONE
);
414 ptid
= ptid_build (pid_of (event_child
), new_pid
, 0);
415 new_lwp
= (struct lwp_info
*) add_lwp (ptid
);
416 add_thread (ptid
, new_lwp
);
418 /* Either we're going to immediately resume the new thread
419 or leave it stopped. linux_resume_one_lwp is a nop if it
420 thinks the thread is currently running, so set this first
421 before calling linux_resume_one_lwp. */
422 new_lwp
->stopped
= 1;
424 /* Normally we will get the pending SIGSTOP. But in some cases
425 we might get another signal delivered to the group first.
426 If we do get another signal, be sure not to lose it. */
427 if (WSTOPSIG (status
) == SIGSTOP
)
429 if (stopping_threads
)
430 new_lwp
->stop_pc
= get_stop_pc (new_lwp
);
432 linux_resume_one_lwp (new_lwp
, 0, 0, NULL
);
436 new_lwp
->stop_expected
= 1;
438 if (stopping_threads
)
440 new_lwp
->stop_pc
= get_stop_pc (new_lwp
);
441 new_lwp
->status_pending_p
= 1;
442 new_lwp
->status_pending
= status
;
445 /* Pass the signal on. This is what GDB does - except
446 shouldn't we really report it instead? */
447 linux_resume_one_lwp (new_lwp
, 0, WSTOPSIG (status
), NULL
);
450 /* Always resume the current thread. If we are stopping
451 threads, it will have a pending SIGSTOP; we may as well
453 linux_resume_one_lwp (event_child
, event_child
->stepping
, 0, NULL
);
457 /* Return the PC as read from the regcache of LWP, without any
461 get_pc (struct lwp_info
*lwp
)
463 struct thread_info
*saved_inferior
;
464 struct regcache
*regcache
;
467 if (the_low_target
.get_pc
== NULL
)
470 saved_inferior
= current_inferior
;
471 current_inferior
= get_lwp_thread (lwp
);
473 regcache
= get_thread_regcache (current_inferior
, 1);
474 pc
= (*the_low_target
.get_pc
) (regcache
);
477 fprintf (stderr
, "pc is 0x%lx\n", (long) pc
);
479 current_inferior
= saved_inferior
;
483 /* This function should only be called if LWP got a SIGTRAP.
484 The SIGTRAP could mean several things.
486 On i386, where decr_pc_after_break is non-zero:
487 If we were single-stepping this process using PTRACE_SINGLESTEP,
488 we will get only the one SIGTRAP (even if the instruction we
489 stepped over was a breakpoint). The value of $eip will be the
491 If we continue the process using PTRACE_CONT, we will get a
492 SIGTRAP when we hit a breakpoint. The value of $eip will be
493 the instruction after the breakpoint (i.e. needs to be
494 decremented). If we report the SIGTRAP to GDB, we must also
495 report the undecremented PC. If we cancel the SIGTRAP, we
496 must resume at the decremented PC.
498 (Presumably, not yet tested) On a non-decr_pc_after_break machine
499 with hardware or kernel single-step:
500 If we single-step over a breakpoint instruction, our PC will
501 point at the following instruction. If we continue and hit a
502 breakpoint instruction, our PC will point at the breakpoint
506 get_stop_pc (struct lwp_info
*lwp
)
510 if (the_low_target
.get_pc
== NULL
)
513 stop_pc
= get_pc (lwp
);
515 if (WSTOPSIG (lwp
->last_status
) == SIGTRAP
517 && !lwp
->stopped_by_watchpoint
518 && lwp
->last_status
>> 16 == 0)
519 stop_pc
-= the_low_target
.decr_pc_after_break
;
522 fprintf (stderr
, "stop pc is 0x%lx\n", (long) stop_pc
);
528 add_lwp (ptid_t ptid
)
530 struct lwp_info
*lwp
;
532 lwp
= (struct lwp_info
*) xmalloc (sizeof (*lwp
));
533 memset (lwp
, 0, sizeof (*lwp
));
537 lwp
->last_resume_kind
= resume_continue
;
539 if (the_low_target
.new_thread
!= NULL
)
540 lwp
->arch_private
= the_low_target
.new_thread ();
542 add_inferior_to_list (&all_lwps
, &lwp
->head
);
547 /* Start an inferior process and returns its pid.
548 ALLARGS is a vector of program-name and args. */
551 linux_create_inferior (char *program
, char **allargs
)
553 struct lwp_info
*new_lwp
;
557 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
563 perror_with_name ("fork");
567 ptrace (PTRACE_TRACEME
, 0, 0, 0);
569 #ifdef __SIGRTMIN /* Bionic doesn't use SIGRTMIN the way glibc does. */
570 signal (__SIGRTMIN
+ 1, SIG_DFL
);
575 execv (program
, allargs
);
577 execvp (program
, allargs
);
579 fprintf (stderr
, "Cannot exec %s: %s.\n", program
,
585 linux_add_process (pid
, 0);
587 ptid
= ptid_build (pid
, pid
, 0);
588 new_lwp
= add_lwp (ptid
);
589 add_thread (ptid
, new_lwp
);
590 new_lwp
->must_set_ptrace_flags
= 1;
595 /* Attach to an inferior process. */
598 linux_attach_lwp_1 (unsigned long lwpid
, int initial
)
601 struct lwp_info
*new_lwp
;
603 if (ptrace (PTRACE_ATTACH
, lwpid
, 0, 0) != 0)
607 /* If we fail to attach to an LWP, just warn. */
608 fprintf (stderr
, "Cannot attach to lwp %ld: %s (%d)\n", lwpid
,
609 strerror (errno
), errno
);
614 /* If we fail to attach to a process, report an error. */
615 error ("Cannot attach to lwp %ld: %s (%d)\n", lwpid
,
616 strerror (errno
), errno
);
620 /* NOTE/FIXME: This lwp might have not been the tgid. */
621 ptid
= ptid_build (lwpid
, lwpid
, 0);
624 /* Note that extracting the pid from the current inferior is
625 safe, since we're always called in the context of the same
626 process as this new thread. */
627 int pid
= pid_of (get_thread_lwp (current_inferior
));
628 ptid
= ptid_build (pid
, lwpid
, 0);
631 new_lwp
= (struct lwp_info
*) add_lwp (ptid
);
632 add_thread (ptid
, new_lwp
);
634 /* We need to wait for SIGSTOP before being able to make the next
635 ptrace call on this LWP. */
636 new_lwp
->must_set_ptrace_flags
= 1;
638 /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
641 There are several cases to consider here:
643 1) gdbserver has already attached to the process and is being notified
644 of a new thread that is being created.
645 In this case we should ignore that SIGSTOP and resume the
646 process. This is handled below by setting stop_expected = 1,
647 and the fact that add_lwp sets last_resume_kind ==
650 2) This is the first thread (the process thread), and we're attaching
651 to it via attach_inferior.
652 In this case we want the process thread to stop.
653 This is handled by having linux_attach set last_resume_kind ==
654 resume_stop after we return.
655 ??? If the process already has several threads we leave the other
658 3) GDB is connecting to gdbserver and is requesting an enumeration of all
660 In this case we want the thread to stop.
661 FIXME: This case is currently not properly handled.
662 We should wait for the SIGSTOP but don't. Things work apparently
663 because enough time passes between when we ptrace (ATTACH) and when
664 gdb makes the next ptrace call on the thread.
666 On the other hand, if we are currently trying to stop all threads, we
667 should treat the new thread as if we had sent it a SIGSTOP. This works
668 because we are guaranteed that the add_lwp call above added us to the
669 end of the list, and so the new thread has not yet reached
670 wait_for_sigstop (but will). */
671 new_lwp
->stop_expected
= 1;
675 linux_attach_lwp (unsigned long lwpid
)
677 linux_attach_lwp_1 (lwpid
, 0);
681 linux_attach (unsigned long pid
)
683 struct lwp_info
*lwp
;
685 linux_attach_lwp_1 (pid
, 1);
687 linux_add_process (pid
, 1);
691 /* Don't ignore the initial SIGSTOP if we just attached to this
692 process. It will be collected by wait shortly. */
693 lwp
= (struct lwp_info
*) find_inferior_id (&all_lwps
,
694 ptid_build (pid
, pid
, 0));
695 lwp
->last_resume_kind
= resume_stop
;
708 second_thread_of_pid_p (struct inferior_list_entry
*entry
, void *args
)
710 struct counter
*counter
= args
;
712 if (ptid_get_pid (entry
->id
) == counter
->pid
)
714 if (++counter
->count
> 1)
722 last_thread_of_process_p (struct thread_info
*thread
)
724 ptid_t ptid
= ((struct inferior_list_entry
*)thread
)->id
;
725 int pid
= ptid_get_pid (ptid
);
726 struct counter counter
= { pid
, 0 };
728 return (find_inferior (&all_threads
,
729 second_thread_of_pid_p
, &counter
) == NULL
);
732 /* Kill the inferior lwp. */
735 linux_kill_one_lwp (struct inferior_list_entry
*entry
, void *args
)
737 struct thread_info
*thread
= (struct thread_info
*) entry
;
738 struct lwp_info
*lwp
= get_thread_lwp (thread
);
740 int pid
= * (int *) args
;
742 if (ptid_get_pid (entry
->id
) != pid
)
745 /* We avoid killing the first thread here, because of a Linux kernel (at
746 least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before
747 the children get a chance to be reaped, it will remain a zombie
750 if (lwpid_of (lwp
) == pid
)
753 fprintf (stderr
, "lkop: is last of process %s\n",
754 target_pid_to_str (entry
->id
));
758 /* If we're killing a running inferior, make sure it is stopped
759 first, as PTRACE_KILL will not work otherwise. */
761 send_sigstop (&lwp
->head
);
765 ptrace (PTRACE_KILL
, lwpid_of (lwp
), 0, 0);
767 /* Make sure it died. The loop is most likely unnecessary. */
768 pid
= linux_wait_for_event (lwp
->head
.id
, &wstat
, __WALL
);
769 } while (pid
> 0 && WIFSTOPPED (wstat
));
777 struct process_info
*process
;
778 struct lwp_info
*lwp
;
779 struct thread_info
*thread
;
783 process
= find_process_pid (pid
);
787 find_inferior (&all_threads
, linux_kill_one_lwp
, &pid
);
789 /* See the comment in linux_kill_one_lwp. We did not kill the first
790 thread in the list, so do so now. */
791 lwp
= find_lwp_pid (pid_to_ptid (pid
));
792 thread
= get_lwp_thread (lwp
);
795 fprintf (stderr
, "lk_1: killing lwp %ld, for pid: %d\n",
796 lwpid_of (lwp
), pid
);
798 /* If we're killing a running inferior, make sure it is stopped
799 first, as PTRACE_KILL will not work otherwise. */
801 send_sigstop (&lwp
->head
);
805 ptrace (PTRACE_KILL
, lwpid_of (lwp
), 0, 0);
807 /* Make sure it died. The loop is most likely unnecessary. */
808 lwpid
= linux_wait_for_event (lwp
->head
.id
, &wstat
, __WALL
);
809 } while (lwpid
> 0 && WIFSTOPPED (wstat
));
812 thread_db_free (process
, 0);
815 linux_remove_process (process
);
820 linux_detach_one_lwp (struct inferior_list_entry
*entry
, void *args
)
822 struct thread_info
*thread
= (struct thread_info
*) entry
;
823 struct lwp_info
*lwp
= get_thread_lwp (thread
);
824 int pid
= * (int *) args
;
826 if (ptid_get_pid (entry
->id
) != pid
)
829 /* If we're detaching from a running inferior, make sure it is
830 stopped first, as PTRACE_DETACH will not work otherwise. */
833 int lwpid
= lwpid_of (lwp
);
835 stopping_threads
= 1;
836 send_sigstop (&lwp
->head
);
838 /* If this detects a new thread through a clone event, the new
839 thread is appended to the end of the lwp list, so we'll
840 eventually detach from it. */
841 wait_for_sigstop (&lwp
->head
);
842 stopping_threads
= 0;
844 /* If LWP exits while we're trying to stop it, there's nothing
846 lwp
= find_lwp_pid (pid_to_ptid (lwpid
));
851 /* If this process is stopped but is expecting a SIGSTOP, then make
852 sure we take care of that now. This isn't absolutely guaranteed
853 to collect the SIGSTOP, but is fairly likely to. */
854 if (lwp
->stop_expected
)
857 /* Clear stop_expected, so that the SIGSTOP will be reported. */
858 lwp
->stop_expected
= 0;
860 linux_resume_one_lwp (lwp
, 0, 0, NULL
);
861 linux_wait_for_event (lwp
->head
.id
, &wstat
, __WALL
);
864 /* Flush any pending changes to the process's registers. */
865 regcache_invalidate_one ((struct inferior_list_entry
*)
866 get_lwp_thread (lwp
));
868 /* Finally, let it resume. */
869 ptrace (PTRACE_DETACH
, lwpid_of (lwp
), 0, 0);
876 any_thread_of (struct inferior_list_entry
*entry
, void *args
)
880 if (ptid_get_pid (entry
->id
) == *pid_p
)
887 linux_detach (int pid
)
889 struct process_info
*process
;
891 process
= find_process_pid (pid
);
896 thread_db_free (process
, 1);
900 (struct thread_info
*) find_inferior (&all_threads
, any_thread_of
, &pid
);
902 delete_all_breakpoints ();
903 find_inferior (&all_threads
, linux_detach_one_lwp
, &pid
);
904 linux_remove_process (process
);
912 struct process_info
*process
;
914 process
= find_process_pid (pid
);
919 ret
= my_waitpid (pid
, &status
, 0);
920 if (WIFEXITED (status
) || WIFSIGNALED (status
))
922 } while (ret
!= -1 || errno
!= ECHILD
);
925 /* Return nonzero if the given thread is still alive. */
927 linux_thread_alive (ptid_t ptid
)
929 struct lwp_info
*lwp
= find_lwp_pid (ptid
);
931 /* We assume we always know if a thread exits. If a whole process
932 exited but we still haven't been able to report it to GDB, we'll
933 hold on to the last lwp of the dead process. */
940 /* Return 1 if this lwp has an interesting status pending. */
942 status_pending_p_callback (struct inferior_list_entry
*entry
, void *arg
)
944 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
945 ptid_t ptid
= * (ptid_t
*) arg
;
946 struct thread_info
*thread
= get_lwp_thread (lwp
);
948 /* Check if we're only interested in events from a specific process
950 if (!ptid_equal (minus_one_ptid
, ptid
)
951 && ptid_get_pid (ptid
) != ptid_get_pid (lwp
->head
.id
))
954 thread
= get_lwp_thread (lwp
);
956 /* If we got a `vCont;t', but we haven't reported a stop yet, do
957 report any status pending the LWP may have. */
958 if (lwp
->last_resume_kind
== resume_stop
959 && thread
->last_status
.kind
== TARGET_WAITKIND_STOPPED
)
962 return lwp
->status_pending_p
;
966 same_lwp (struct inferior_list_entry
*entry
, void *data
)
968 ptid_t ptid
= *(ptid_t
*) data
;
971 if (ptid_get_lwp (ptid
) != 0)
972 lwp
= ptid_get_lwp (ptid
);
974 lwp
= ptid_get_pid (ptid
);
976 if (ptid_get_lwp (entry
->id
) == lwp
)
983 find_lwp_pid (ptid_t ptid
)
985 return (struct lwp_info
*) find_inferior (&all_lwps
, same_lwp
, &ptid
);
988 static struct lwp_info
*
989 linux_wait_for_lwp (ptid_t ptid
, int *wstatp
, int options
)
992 int to_wait_for
= -1;
993 struct lwp_info
*child
= NULL
;
996 fprintf (stderr
, "linux_wait_for_lwp: %s\n", target_pid_to_str (ptid
));
998 if (ptid_equal (ptid
, minus_one_ptid
))
999 to_wait_for
= -1; /* any child */
1001 to_wait_for
= ptid_get_lwp (ptid
); /* this lwp only */
1007 ret
= my_waitpid (to_wait_for
, wstatp
, options
);
1008 if (ret
== 0 || (ret
== -1 && errno
== ECHILD
&& (options
& WNOHANG
)))
1011 perror_with_name ("waitpid");
1014 && (!WIFSTOPPED (*wstatp
)
1015 || (WSTOPSIG (*wstatp
) != 32
1016 && WSTOPSIG (*wstatp
) != 33)))
1017 fprintf (stderr
, "Got an event from %d (%x)\n", ret
, *wstatp
);
1019 child
= find_lwp_pid (pid_to_ptid (ret
));
1021 /* If we didn't find a process, one of two things presumably happened:
1022 - A process we started and then detached from has exited. Ignore it.
1023 - A process we are controlling has forked and the new child's stop
1024 was reported to us by the kernel. Save its PID. */
1025 if (child
== NULL
&& WIFSTOPPED (*wstatp
))
1027 add_pid_to_list (&stopped_pids
, ret
);
1030 else if (child
== NULL
)
1035 child
->last_status
= *wstatp
;
1037 /* Architecture-specific setup after inferior is running.
1038 This needs to happen after we have attached to the inferior
1039 and it is stopped for the first time, but before we access
1040 any inferior registers. */
1043 the_low_target
.arch_setup ();
1044 #ifdef HAVE_LINUX_REGSETS
1045 memset (disabled_regsets
, 0, num_regsets
);
1050 /* Fetch the possibly triggered data watchpoint info and store it in
1053 On some archs, like x86, that use debug registers to set
1054 watchpoints, it's possible that the way to know which watched
1055 address trapped, is to check the register that is used to select
1056 which address to watch. Problem is, between setting the
1057 watchpoint and reading back which data address trapped, the user
1058 may change the set of watchpoints, and, as a consequence, GDB
1059 changes the debug registers in the inferior. To avoid reading
1060 back a stale stopped-data-address when that happens, we cache in
1061 LP the fact that a watchpoint trapped, and the corresponding data
1062 address, as soon as we see CHILD stop with a SIGTRAP. If GDB
1063 changes the debug registers meanwhile, we have the cached data we
1066 if (WIFSTOPPED (*wstatp
) && WSTOPSIG (*wstatp
) == SIGTRAP
)
1068 if (the_low_target
.stopped_by_watchpoint
== NULL
)
1070 child
->stopped_by_watchpoint
= 0;
1074 struct thread_info
*saved_inferior
;
1076 saved_inferior
= current_inferior
;
1077 current_inferior
= get_lwp_thread (child
);
1079 child
->stopped_by_watchpoint
1080 = the_low_target
.stopped_by_watchpoint ();
1082 if (child
->stopped_by_watchpoint
)
1084 if (the_low_target
.stopped_data_address
!= NULL
)
1085 child
->stopped_data_address
1086 = the_low_target
.stopped_data_address ();
1088 child
->stopped_data_address
= 0;
1091 current_inferior
= saved_inferior
;
1095 /* Store the STOP_PC, with adjustment applied. This depends on the
1096 architecture being defined already (so that CHILD has a valid
1097 regcache), and on LAST_STATUS being set (to check for SIGTRAP or
1099 if (WIFSTOPPED (*wstatp
))
1100 child
->stop_pc
= get_stop_pc (child
);
1103 && WIFSTOPPED (*wstatp
)
1104 && the_low_target
.get_pc
!= NULL
)
1106 struct thread_info
*saved_inferior
= current_inferior
;
1107 struct regcache
*regcache
;
1110 current_inferior
= get_lwp_thread (child
);
1111 regcache
= get_thread_regcache (current_inferior
, 1);
1112 pc
= (*the_low_target
.get_pc
) (regcache
);
1113 fprintf (stderr
, "linux_wait_for_lwp: pc is 0x%lx\n", (long) pc
);
1114 current_inferior
= saved_inferior
;
1120 /* Arrange for a breakpoint to be hit again later. We don't keep the
1121 SIGTRAP status and don't forward the SIGTRAP signal to the LWP. We
1122 will handle the current event, eventually we will resume this LWP,
1123 and this breakpoint will trap again. */
1126 cancel_breakpoint (struct lwp_info
*lwp
)
1128 struct thread_info
*saved_inferior
;
1130 /* There's nothing to do if we don't support breakpoints. */
1131 if (!supports_breakpoints ())
1134 /* breakpoint_at reads from current inferior. */
1135 saved_inferior
= current_inferior
;
1136 current_inferior
= get_lwp_thread (lwp
);
1138 if ((*the_low_target
.breakpoint_at
) (lwp
->stop_pc
))
1142 "CB: Push back breakpoint for %s\n",
1143 target_pid_to_str (ptid_of (lwp
)));
1145 /* Back up the PC if necessary. */
1146 if (the_low_target
.decr_pc_after_break
)
1148 struct regcache
*regcache
1149 = get_thread_regcache (current_inferior
, 1);
1150 (*the_low_target
.set_pc
) (regcache
, lwp
->stop_pc
);
1153 current_inferior
= saved_inferior
;
1160 "CB: No breakpoint found at %s for [%s]\n",
1161 paddress (lwp
->stop_pc
),
1162 target_pid_to_str (ptid_of (lwp
)));
1165 current_inferior
= saved_inferior
;
1169 /* When the event-loop is doing a step-over, this points at the thread
1171 ptid_t step_over_bkpt
;
1173 /* Wait for an event from child PID. If PID is -1, wait for any
1174 child. Store the stop status through the status pointer WSTAT.
1175 OPTIONS is passed to the waitpid call. Return 0 if no child stop
1176 event was found and OPTIONS contains WNOHANG. Return the PID of
1177 the stopped child otherwise. */
1180 linux_wait_for_event_1 (ptid_t ptid
, int *wstat
, int options
)
1182 struct lwp_info
*event_child
, *requested_child
;
1185 requested_child
= NULL
;
1187 /* Check for a lwp with a pending status. */
1189 if (ptid_equal (ptid
, minus_one_ptid
)
1190 || ptid_equal (pid_to_ptid (ptid_get_pid (ptid
)), ptid
))
1192 event_child
= (struct lwp_info
*)
1193 find_inferior (&all_lwps
, status_pending_p_callback
, &ptid
);
1194 if (debug_threads
&& event_child
)
1195 fprintf (stderr
, "Got a pending child %ld\n", lwpid_of (event_child
));
1199 requested_child
= find_lwp_pid (ptid
);
1201 if (requested_child
->status_pending_p
)
1202 event_child
= requested_child
;
1205 if (event_child
!= NULL
)
1208 fprintf (stderr
, "Got an event from pending child %ld (%04x)\n",
1209 lwpid_of (event_child
), event_child
->status_pending
);
1210 *wstat
= event_child
->status_pending
;
1211 event_child
->status_pending_p
= 0;
1212 event_child
->status_pending
= 0;
1213 current_inferior
= get_lwp_thread (event_child
);
1214 return lwpid_of (event_child
);
1217 /* We only enter this loop if no process has a pending wait status. Thus
1218 any action taken in response to a wait status inside this loop is
1219 responding as soon as we detect the status, not after any pending
1223 event_child
= linux_wait_for_lwp (ptid
, wstat
, options
);
1225 if ((options
& WNOHANG
) && event_child
== NULL
)
1228 fprintf (stderr
, "WNOHANG set, no event found\n");
1232 if (event_child
== NULL
)
1233 error ("event from unknown child");
1235 current_inferior
= get_lwp_thread (event_child
);
1237 /* Check for thread exit. */
1238 if (! WIFSTOPPED (*wstat
))
1241 fprintf (stderr
, "LWP %ld exiting\n", lwpid_of (event_child
));
1243 /* If the last thread is exiting, just return. */
1244 if (last_thread_of_process_p (current_inferior
))
1247 fprintf (stderr
, "LWP %ld is last lwp of process\n",
1248 lwpid_of (event_child
));
1249 return lwpid_of (event_child
);
1254 current_inferior
= (struct thread_info
*) all_threads
.head
;
1256 fprintf (stderr
, "Current inferior is now %ld\n",
1257 lwpid_of (get_thread_lwp (current_inferior
)));
1261 current_inferior
= NULL
;
1263 fprintf (stderr
, "Current inferior is now <NULL>\n");
1266 /* If we were waiting for this particular child to do something...
1267 well, it did something. */
1268 if (requested_child
!= NULL
)
1270 int lwpid
= lwpid_of (event_child
);
1272 /* Cancel the step-over operation --- the thread that
1273 started it is gone. */
1274 if (finish_step_over (event_child
))
1275 unstop_all_lwps (event_child
);
1276 delete_lwp (event_child
);
1280 delete_lwp (event_child
);
1282 /* Wait for a more interesting event. */
1286 if (event_child
->must_set_ptrace_flags
)
1288 ptrace (PTRACE_SETOPTIONS
, lwpid_of (event_child
),
1289 0, (PTRACE_ARG4_TYPE
) PTRACE_O_TRACECLONE
);
1290 event_child
->must_set_ptrace_flags
= 0;
1293 if (WIFSTOPPED (*wstat
) && WSTOPSIG (*wstat
) == SIGTRAP
1294 && *wstat
>> 16 != 0)
1296 handle_extended_wait (event_child
, *wstat
);
1300 /* If GDB is not interested in this signal, don't stop other
1301 threads, and don't report it to GDB. Just resume the
1302 inferior right away. We do this for threading-related
1303 signals as well as any that GDB specifically requested we
1304 ignore. But never ignore SIGSTOP if we sent it ourselves,
1305 and do not ignore signals when stepping - they may require
1306 special handling to skip the signal handler. */
1307 /* FIXME drow/2002-06-09: Get signal numbers from the inferior's
1309 if (WIFSTOPPED (*wstat
)
1310 && !event_child
->stepping
1312 #if defined (USE_THREAD_DB) && defined (__SIGRTMIN)
1313 (current_process ()->private->thread_db
!= NULL
1314 && (WSTOPSIG (*wstat
) == __SIGRTMIN
1315 || WSTOPSIG (*wstat
) == __SIGRTMIN
+ 1))
1318 (pass_signals
[target_signal_from_host (WSTOPSIG (*wstat
))]
1319 && !(WSTOPSIG (*wstat
) == SIGSTOP
1320 && event_child
->stop_expected
))))
1322 siginfo_t info
, *info_p
;
1325 fprintf (stderr
, "Ignored signal %d for LWP %ld.\n",
1326 WSTOPSIG (*wstat
), lwpid_of (event_child
));
1328 if (ptrace (PTRACE_GETSIGINFO
, lwpid_of (event_child
), 0, &info
) == 0)
1332 linux_resume_one_lwp (event_child
, event_child
->stepping
,
1333 WSTOPSIG (*wstat
), info_p
);
1337 if (WIFSTOPPED (*wstat
)
1338 && WSTOPSIG (*wstat
) == SIGSTOP
1339 && event_child
->stop_expected
)
1344 fprintf (stderr
, "Expected stop.\n");
1345 event_child
->stop_expected
= 0;
1347 should_stop
= (event_child
->last_resume_kind
== resume_stop
1348 || stopping_threads
);
1352 linux_resume_one_lwp (event_child
,
1353 event_child
->stepping
, 0, NULL
);
1358 return lwpid_of (event_child
);
1366 linux_wait_for_event (ptid_t ptid
, int *wstat
, int options
)
1370 if (ptid_is_pid (ptid
))
1372 /* A request to wait for a specific tgid. This is not possible
1373 with waitpid, so instead, we wait for any child, and leave
1374 children we're not interested in right now with a pending
1375 status to report later. */
1376 wait_ptid
= minus_one_ptid
;
1385 event_pid
= linux_wait_for_event_1 (wait_ptid
, wstat
, options
);
1388 && ptid_is_pid (ptid
) && ptid_get_pid (ptid
) != event_pid
)
1390 struct lwp_info
*event_child
= find_lwp_pid (pid_to_ptid (event_pid
));
1392 if (! WIFSTOPPED (*wstat
))
1393 mark_lwp_dead (event_child
, *wstat
);
1396 event_child
->status_pending_p
= 1;
1397 event_child
->status_pending
= *wstat
;
1406 /* Count the LWP's that have had events. */
1409 count_events_callback (struct inferior_list_entry
*entry
, void *data
)
1411 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
1414 gdb_assert (count
!= NULL
);
1416 /* Count only resumed LWPs that have a SIGTRAP event pending that
1417 should be reported to GDB. */
1418 if (get_lwp_thread (lp
)->last_status
.kind
== TARGET_WAITKIND_IGNORE
1419 && lp
->last_resume_kind
!= resume_stop
1420 && lp
->status_pending_p
1421 && WIFSTOPPED (lp
->status_pending
)
1422 && WSTOPSIG (lp
->status_pending
) == SIGTRAP
1423 && !breakpoint_inserted_here (lp
->stop_pc
))
1429 /* Select the LWP (if any) that is currently being single-stepped. */
1432 select_singlestep_lwp_callback (struct inferior_list_entry
*entry
, void *data
)
1434 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
1436 if (get_lwp_thread (lp
)->last_status
.kind
== TARGET_WAITKIND_IGNORE
1437 && lp
->last_resume_kind
== resume_step
1438 && lp
->status_pending_p
)
1444 /* Select the Nth LWP that has had a SIGTRAP event that should be
1448 select_event_lwp_callback (struct inferior_list_entry
*entry
, void *data
)
1450 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
1451 int *selector
= data
;
1453 gdb_assert (selector
!= NULL
);
1455 /* Select only resumed LWPs that have a SIGTRAP event pending. */
1456 if (lp
->last_resume_kind
!= resume_stop
1457 && get_lwp_thread (lp
)->last_status
.kind
== TARGET_WAITKIND_IGNORE
1458 && lp
->status_pending_p
1459 && WIFSTOPPED (lp
->status_pending
)
1460 && WSTOPSIG (lp
->status_pending
) == SIGTRAP
1461 && !breakpoint_inserted_here (lp
->stop_pc
))
1462 if ((*selector
)-- == 0)
1469 cancel_breakpoints_callback (struct inferior_list_entry
*entry
, void *data
)
1471 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
1472 struct lwp_info
*event_lp
= data
;
1474 /* Leave the LWP that has been elected to receive a SIGTRAP alone. */
1478 /* If a LWP other than the LWP that we're reporting an event for has
1479 hit a GDB breakpoint (as opposed to some random trap signal),
1480 then just arrange for it to hit it again later. We don't keep
1481 the SIGTRAP status and don't forward the SIGTRAP signal to the
1482 LWP. We will handle the current event, eventually we will resume
1483 all LWPs, and this one will get its breakpoint trap again.
1485 If we do not do this, then we run the risk that the user will
1486 delete or disable the breakpoint, but the LWP will have already
1489 if (lp
->last_resume_kind
!= resume_stop
1490 && get_lwp_thread (lp
)->last_status
.kind
== TARGET_WAITKIND_IGNORE
1491 && lp
->status_pending_p
1492 && WIFSTOPPED (lp
->status_pending
)
1493 && WSTOPSIG (lp
->status_pending
) == SIGTRAP
1495 && !lp
->stopped_by_watchpoint
1496 && cancel_breakpoint (lp
))
1497 /* Throw away the SIGTRAP. */
1498 lp
->status_pending_p
= 0;
1503 /* Select one LWP out of those that have events pending. */
1506 select_event_lwp (struct lwp_info
**orig_lp
)
1509 int random_selector
;
1510 struct lwp_info
*event_lp
;
1512 /* Give preference to any LWP that is being single-stepped. */
1514 = (struct lwp_info
*) find_inferior (&all_lwps
,
1515 select_singlestep_lwp_callback
, NULL
);
1516 if (event_lp
!= NULL
)
1520 "SEL: Select single-step %s\n",
1521 target_pid_to_str (ptid_of (event_lp
)));
1525 /* No single-stepping LWP. Select one at random, out of those
1526 which have had SIGTRAP events. */
1528 /* First see how many SIGTRAP events we have. */
1529 find_inferior (&all_lwps
, count_events_callback
, &num_events
);
1531 /* Now randomly pick a LWP out of those that have had a SIGTRAP. */
1532 random_selector
= (int)
1533 ((num_events
* (double) rand ()) / (RAND_MAX
+ 1.0));
1535 if (debug_threads
&& num_events
> 1)
1537 "SEL: Found %d SIGTRAP events, selecting #%d\n",
1538 num_events
, random_selector
);
1540 event_lp
= (struct lwp_info
*) find_inferior (&all_lwps
,
1541 select_event_lwp_callback
,
1545 if (event_lp
!= NULL
)
1547 /* Switch the event LWP. */
1548 *orig_lp
= event_lp
;
1552 /* Set this inferior LWP's state as "want-stopped". We won't resume
1553 this LWP until the client gives us another action for it. */
1556 gdb_wants_lwp_stopped (struct inferior_list_entry
*entry
)
1558 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
1559 struct thread_info
*thread
= get_lwp_thread (lwp
);
1561 /* Most threads are stopped implicitly (all-stop); tag that with
1562 signal 0. The thread being explicitly reported stopped to the
1563 client, gets it's status fixed up afterwards. */
1564 thread
->last_status
.kind
= TARGET_WAITKIND_STOPPED
;
1565 thread
->last_status
.value
.sig
= TARGET_SIGNAL_0
;
1567 lwp
->last_resume_kind
= resume_stop
;
1570 /* Set all LWP's states as "want-stopped". */
1573 gdb_wants_all_stopped (void)
1575 for_each_inferior (&all_lwps
, gdb_wants_lwp_stopped
);
1578 /* Wait for process, returns status. */
1581 linux_wait_1 (ptid_t ptid
,
1582 struct target_waitstatus
*ourstatus
, int target_options
)
1585 struct lwp_info
*event_child
;
1588 int step_over_finished
;
1589 int bp_explains_trap
;
1590 int maybe_internal_trap
;
1593 /* Translate generic target options into linux options. */
1595 if (target_options
& TARGET_WNOHANG
)
1599 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
1601 /* If we were only supposed to resume one thread, only wait for
1602 that thread - if it's still alive. If it died, however - which
1603 can happen if we're coming from the thread death case below -
1604 then we need to make sure we restart the other threads. We could
1605 pick a thread at random or restart all; restarting all is less
1608 && !ptid_equal (cont_thread
, null_ptid
)
1609 && !ptid_equal (cont_thread
, minus_one_ptid
))
1611 struct thread_info
*thread
;
1613 thread
= (struct thread_info
*) find_inferior_id (&all_threads
,
1616 /* No stepping, no signal - unless one is pending already, of course. */
1619 struct thread_resume resume_info
;
1620 resume_info
.thread
= minus_one_ptid
;
1621 resume_info
.kind
= resume_continue
;
1622 resume_info
.sig
= 0;
1623 linux_resume (&resume_info
, 1);
1629 if (ptid_equal (step_over_bkpt
, null_ptid
))
1630 pid
= linux_wait_for_event (ptid
, &w
, options
);
1634 fprintf (stderr
, "step_over_bkpt set [%s], doing a blocking wait\n",
1635 target_pid_to_str (step_over_bkpt
));
1636 pid
= linux_wait_for_event (step_over_bkpt
, &w
, options
& ~WNOHANG
);
1639 if (pid
== 0) /* only if TARGET_WNOHANG */
1642 event_child
= get_thread_lwp (current_inferior
);
1644 /* If we are waiting for a particular child, and it exited,
1645 linux_wait_for_event will return its exit status. Similarly if
1646 the last child exited. If this is not the last child, however,
1647 do not report it as exited until there is a 'thread exited' response
1648 available in the remote protocol. Instead, just wait for another event.
1649 This should be safe, because if the thread crashed we will already
1650 have reported the termination signal to GDB; that should stop any
1651 in-progress stepping operations, etc.
1653 Report the exit status of the last thread to exit. This matches
1654 LinuxThreads' behavior. */
1656 if (last_thread_of_process_p (current_inferior
))
1658 if (WIFEXITED (w
) || WIFSIGNALED (w
))
1660 int pid
= pid_of (event_child
);
1661 struct process_info
*process
= find_process_pid (pid
);
1663 #ifdef USE_THREAD_DB
1664 thread_db_free (process
, 0);
1666 delete_lwp (event_child
);
1667 linux_remove_process (process
);
1669 current_inferior
= NULL
;
1673 ourstatus
->kind
= TARGET_WAITKIND_EXITED
;
1674 ourstatus
->value
.integer
= WEXITSTATUS (w
);
1677 fprintf (stderr
, "\nChild exited with retcode = %x \n", WEXITSTATUS (w
));
1681 ourstatus
->kind
= TARGET_WAITKIND_SIGNALLED
;
1682 ourstatus
->value
.sig
= target_signal_from_host (WTERMSIG (w
));
1685 fprintf (stderr
, "\nChild terminated with signal = %x \n", WTERMSIG (w
));
1689 return pid_to_ptid (pid
);
1694 if (!WIFSTOPPED (w
))
1698 /* If this event was not handled before, and is not a SIGTRAP, we
1699 report it. SIGILL and SIGSEGV are also treated as traps in case
1700 a breakpoint is inserted at the current PC. If this target does
1701 not support internal breakpoints at all, we also report the
1702 SIGTRAP without further processing; it's of no concern to us. */
1704 = (supports_breakpoints ()
1705 && (WSTOPSIG (w
) == SIGTRAP
1706 || ((WSTOPSIG (w
) == SIGILL
1707 || WSTOPSIG (w
) == SIGSEGV
)
1708 && (*the_low_target
.breakpoint_at
) (event_child
->stop_pc
))));
1710 if (maybe_internal_trap
)
1712 /* Handle anything that requires bookkeeping before deciding to
1713 report the event or continue waiting. */
1715 /* First check if we can explain the SIGTRAP with an internal
1716 breakpoint, or if we should possibly report the event to GDB.
1717 Do this before anything that may remove or insert a
1719 bp_explains_trap
= breakpoint_inserted_here (event_child
->stop_pc
);
1721 /* We have a SIGTRAP, possibly a step-over dance has just
1722 finished. If so, tweak the state machine accordingly,
1723 reinsert breakpoints and delete any reinsert (software
1724 single-step) breakpoints. */
1725 step_over_finished
= finish_step_over (event_child
);
1727 /* Now invoke the callbacks of any internal breakpoints there. */
1728 check_breakpoints (event_child
->stop_pc
);
1730 if (bp_explains_trap
)
1732 /* If we stepped or ran into an internal breakpoint, we've
1733 already handled it. So next time we resume (from this
1734 PC), we should step over it. */
1736 fprintf (stderr
, "Hit a gdbserver breakpoint.\n");
1738 if (breakpoint_here (event_child
->stop_pc
))
1739 event_child
->need_step_over
= 1;
1744 /* We have some other signal, possibly a step-over dance was in
1745 progress, and it should be cancelled too. */
1746 step_over_finished
= finish_step_over (event_child
);
1749 /* We have all the data we need. Either report the event to GDB, or
1750 resume threads and keep waiting for more. */
1752 /* Check If GDB would be interested in this event. If GDB wanted
1753 this thread to single step, we always want to report the SIGTRAP,
1754 and let GDB handle it. Watchpoints should always be reported.
1755 So should signals we can't explain. A SIGTRAP we can't explain
1756 could be a GDB breakpoint --- we may or not support Z0
1757 breakpoints. If we do, we're be able to handle GDB breakpoints
1758 on top of internal breakpoints, by handling the internal
1759 breakpoint and still reporting the event to GDB. If we don't,
1760 we're out of luck, GDB won't see the breakpoint hit. */
1761 report_to_gdb
= (!maybe_internal_trap
1762 || event_child
->last_resume_kind
== resume_step
1763 || event_child
->stopped_by_watchpoint
1764 || (!step_over_finished
&& !bp_explains_trap
)
1765 || gdb_breakpoint_here (event_child
->stop_pc
));
1767 /* We found no reason GDB would want us to stop. We either hit one
1768 of our own breakpoints, or finished an internal step GDB
1769 shouldn't know about. */
1774 if (bp_explains_trap
)
1775 fprintf (stderr
, "Hit a gdbserver breakpoint.\n");
1776 if (step_over_finished
)
1777 fprintf (stderr
, "Step-over finished.\n");
1780 /* We're not reporting this breakpoint to GDB, so apply the
1781 decr_pc_after_break adjustment to the inferior's regcache
1784 if (the_low_target
.set_pc
!= NULL
)
1786 struct regcache
*regcache
1787 = get_thread_regcache (get_lwp_thread (event_child
), 1);
1788 (*the_low_target
.set_pc
) (regcache
, event_child
->stop_pc
);
1791 /* We've finished stepping over a breakpoint. We've stopped all
1792 LWPs momentarily except the stepping one. This is where we
1793 resume them all again. We're going to keep waiting, so use
1794 proceed, which handles stepping over the next breakpoint. */
1796 fprintf (stderr
, "proceeding all threads.\n");
1797 proceed_all_lwps ();
1803 if (event_child
->last_resume_kind
== resume_step
)
1804 fprintf (stderr
, "GDB wanted to single-step, reporting event.\n");
1805 if (event_child
->stopped_by_watchpoint
)
1806 fprintf (stderr
, "Stopped by watchpoint.\n");
1807 if (gdb_breakpoint_here (event_child
->stop_pc
))
1808 fprintf (stderr
, "Stopped by GDB breakpoint.\n");
1810 fprintf (stderr
, "Hit a non-gdbserver trap event.\n");
1813 /* Alright, we're going to report a stop. */
1817 /* In all-stop, stop all threads. */
1820 /* If we're not waiting for a specific LWP, choose an event LWP
1821 from among those that have had events. Giving equal priority
1822 to all LWPs that have had events helps prevent
1824 if (ptid_equal (ptid
, minus_one_ptid
))
1826 event_child
->status_pending_p
= 1;
1827 event_child
->status_pending
= w
;
1829 select_event_lwp (&event_child
);
1831 event_child
->status_pending_p
= 0;
1832 w
= event_child
->status_pending
;
1835 /* Now that we've selected our final event LWP, cancel any
1836 breakpoints in other LWPs that have hit a GDB breakpoint.
1837 See the comment in cancel_breakpoints_callback to find out
1839 find_inferior (&all_lwps
, cancel_breakpoints_callback
, event_child
);
1843 /* If we just finished a step-over, then all threads had been
1844 momentarily paused. In all-stop, that's fine, we want
1845 threads stopped by now anyway. In non-stop, we need to
1846 re-resume threads that GDB wanted to be running. */
1847 if (step_over_finished
)
1848 unstop_all_lwps (event_child
);
1851 ourstatus
->kind
= TARGET_WAITKIND_STOPPED
;
1853 /* Do this before the gdb_wants_all_stopped calls below, since they
1854 always set last_resume_kind to resume_stop. */
1855 if (event_child
->last_resume_kind
== resume_stop
&& WSTOPSIG (w
) == SIGSTOP
)
1857 /* A thread that has been requested to stop by GDB with vCont;t,
1858 and it stopped cleanly, so report as SIG0. The use of
1859 SIGSTOP is an implementation detail. */
1860 ourstatus
->value
.sig
= TARGET_SIGNAL_0
;
1862 else if (event_child
->last_resume_kind
== resume_stop
&& WSTOPSIG (w
) != SIGSTOP
)
1864 /* A thread that has been requested to stop by GDB with vCont;t,
1865 but, it stopped for other reasons. */
1866 ourstatus
->value
.sig
= target_signal_from_host (WSTOPSIG (w
));
1870 ourstatus
->value
.sig
= target_signal_from_host (WSTOPSIG (w
));
1873 gdb_assert (ptid_equal (step_over_bkpt
, null_ptid
));
1877 /* From GDB's perspective, all-stop mode always stops all
1878 threads implicitly. Tag all threads as "want-stopped". */
1879 gdb_wants_all_stopped ();
1883 /* We're reporting this LWP as stopped. Update it's
1884 "want-stopped" state to what the client wants, until it gets
1885 a new resume action. */
1886 gdb_wants_lwp_stopped (&event_child
->head
);
1890 fprintf (stderr
, "linux_wait ret = %s, %d, %d\n",
1891 target_pid_to_str (ptid_of (event_child
)),
1893 ourstatus
->value
.sig
);
1895 get_lwp_thread (event_child
)->last_status
= *ourstatus
;
1896 return ptid_of (event_child
);
1899 /* Get rid of any pending event in the pipe. */
1901 async_file_flush (void)
1907 ret
= read (linux_event_pipe
[0], &buf
, 1);
1908 while (ret
>= 0 || (ret
== -1 && errno
== EINTR
));
1911 /* Put something in the pipe, so the event loop wakes up. */
1913 async_file_mark (void)
1917 async_file_flush ();
1920 ret
= write (linux_event_pipe
[1], "+", 1);
1921 while (ret
== 0 || (ret
== -1 && errno
== EINTR
));
1923 /* Ignore EAGAIN. If the pipe is full, the event loop will already
1924 be awakened anyway. */
1928 linux_wait (ptid_t ptid
,
1929 struct target_waitstatus
*ourstatus
, int target_options
)
1934 fprintf (stderr
, "linux_wait: [%s]\n", target_pid_to_str (ptid
));
1936 /* Flush the async file first. */
1937 if (target_is_async_p ())
1938 async_file_flush ();
1940 event_ptid
= linux_wait_1 (ptid
, ourstatus
, target_options
);
1942 /* If at least one stop was reported, there may be more. A single
1943 SIGCHLD can signal more than one child stop. */
1944 if (target_is_async_p ()
1945 && (target_options
& TARGET_WNOHANG
) != 0
1946 && !ptid_equal (event_ptid
, null_ptid
))
1952 /* Send a signal to an LWP. */
1955 kill_lwp (unsigned long lwpid
, int signo
)
1957 /* Use tkill, if possible, in case we are using nptl threads. If tkill
1958 fails, then we are not using nptl threads and we should be using kill. */
1962 static int tkill_failed
;
1969 ret
= syscall (__NR_tkill
, lwpid
, signo
);
1970 if (errno
!= ENOSYS
)
1977 return kill (lwpid
, signo
);
1981 send_sigstop (struct inferior_list_entry
*entry
)
1983 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
1989 pid
= lwpid_of (lwp
);
1991 /* If we already have a pending stop signal for this process, don't
1993 if (lwp
->stop_expected
)
1996 fprintf (stderr
, "Have pending sigstop for lwp %d\n", pid
);
2002 fprintf (stderr
, "Sending sigstop to lwp %d\n", pid
);
2004 lwp
->stop_expected
= 1;
2005 kill_lwp (pid
, SIGSTOP
);
2009 mark_lwp_dead (struct lwp_info
*lwp
, int wstat
)
2011 /* It's dead, really. */
2014 /* Store the exit status for later. */
2015 lwp
->status_pending_p
= 1;
2016 lwp
->status_pending
= wstat
;
2018 /* Prevent trying to stop it. */
2021 /* No further stops are expected from a dead lwp. */
2022 lwp
->stop_expected
= 0;
2026 wait_for_sigstop (struct inferior_list_entry
*entry
)
2028 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2029 struct thread_info
*saved_inferior
;
2038 fprintf (stderr
, "wait_for_sigstop: LWP %ld already stopped\n",
2043 saved_inferior
= current_inferior
;
2044 if (saved_inferior
!= NULL
)
2045 saved_tid
= ((struct inferior_list_entry
*) saved_inferior
)->id
;
2047 saved_tid
= null_ptid
; /* avoid bogus unused warning */
2049 ptid
= lwp
->head
.id
;
2052 fprintf (stderr
, "wait_for_sigstop: pulling one event\n");
2054 pid
= linux_wait_for_event (ptid
, &wstat
, __WALL
);
2056 /* If we stopped with a non-SIGSTOP signal, save it for later
2057 and record the pending SIGSTOP. If the process exited, just
2059 if (WIFSTOPPED (wstat
))
2062 fprintf (stderr
, "LWP %ld stopped with signal %d\n",
2063 lwpid_of (lwp
), WSTOPSIG (wstat
));
2065 if (WSTOPSIG (wstat
) != SIGSTOP
)
2068 fprintf (stderr
, "LWP %ld stopped with non-sigstop status %06x\n",
2069 lwpid_of (lwp
), wstat
);
2071 lwp
->status_pending_p
= 1;
2072 lwp
->status_pending
= wstat
;
2078 fprintf (stderr
, "Process %d exited while stopping LWPs\n", pid
);
2080 lwp
= find_lwp_pid (pid_to_ptid (pid
));
2083 /* Leave this status pending for the next time we're able to
2084 report it. In the mean time, we'll report this lwp as
2085 dead to GDB, so GDB doesn't try to read registers and
2086 memory from it. This can only happen if this was the
2087 last thread of the process; otherwise, PID is removed
2088 from the thread tables before linux_wait_for_event
2090 mark_lwp_dead (lwp
, wstat
);
2094 if (saved_inferior
== NULL
|| linux_thread_alive (saved_tid
))
2095 current_inferior
= saved_inferior
;
2099 fprintf (stderr
, "Previously current thread died.\n");
2103 /* We can't change the current inferior behind GDB's back,
2104 otherwise, a subsequent command may apply to the wrong
2106 current_inferior
= NULL
;
2110 /* Set a valid thread as current. */
2111 set_desired_inferior (0);
2117 stop_all_lwps (void)
2119 stopping_threads
= 1;
2120 for_each_inferior (&all_lwps
, send_sigstop
);
2121 for_each_inferior (&all_lwps
, wait_for_sigstop
);
2122 stopping_threads
= 0;
2125 /* Resume execution of the inferior process.
2126 If STEP is nonzero, single-step it.
2127 If SIGNAL is nonzero, give it that signal. */
2130 linux_resume_one_lwp (struct lwp_info
*lwp
,
2131 int step
, int signal
, siginfo_t
*info
)
2133 struct thread_info
*saved_inferior
;
2135 if (lwp
->stopped
== 0)
2138 /* If we have pending signals or status, and a new signal, enqueue the
2139 signal. Also enqueue the signal if we are waiting to reinsert a
2140 breakpoint; it will be picked up again below. */
2142 && (lwp
->status_pending_p
|| lwp
->pending_signals
!= NULL
2143 || lwp
->bp_reinsert
!= 0))
2145 struct pending_signals
*p_sig
;
2146 p_sig
= xmalloc (sizeof (*p_sig
));
2147 p_sig
->prev
= lwp
->pending_signals
;
2148 p_sig
->signal
= signal
;
2150 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
2152 memcpy (&p_sig
->info
, info
, sizeof (siginfo_t
));
2153 lwp
->pending_signals
= p_sig
;
2156 if (lwp
->status_pending_p
)
2159 fprintf (stderr
, "Not resuming lwp %ld (%s, signal %d, stop %s);"
2160 " has pending status\n",
2161 lwpid_of (lwp
), step
? "step" : "continue", signal
,
2162 lwp
->stop_expected
? "expected" : "not expected");
2166 saved_inferior
= current_inferior
;
2167 current_inferior
= get_lwp_thread (lwp
);
2170 fprintf (stderr
, "Resuming lwp %ld (%s, signal %d, stop %s)\n",
2171 lwpid_of (lwp
), step
? "step" : "continue", signal
,
2172 lwp
->stop_expected
? "expected" : "not expected");
2174 /* This bit needs some thinking about. If we get a signal that
2175 we must report while a single-step reinsert is still pending,
2176 we often end up resuming the thread. It might be better to
2177 (ew) allow a stack of pending events; then we could be sure that
2178 the reinsert happened right away and not lose any signals.
2180 Making this stack would also shrink the window in which breakpoints are
2181 uninserted (see comment in linux_wait_for_lwp) but not enough for
2182 complete correctness, so it won't solve that problem. It may be
2183 worthwhile just to solve this one, however. */
2184 if (lwp
->bp_reinsert
!= 0)
2187 fprintf (stderr
, " pending reinsert at 0x%s\n",
2188 paddress (lwp
->bp_reinsert
));
2190 if (lwp
->bp_reinsert
!= 0 && can_hardware_single_step ())
2193 fprintf (stderr
, "BAD - reinserting but not stepping.\n");
2198 /* Postpone any pending signal. It was enqueued above. */
2202 if (debug_threads
&& the_low_target
.get_pc
!= NULL
)
2204 struct regcache
*regcache
= get_thread_regcache (current_inferior
, 1);
2205 CORE_ADDR pc
= (*the_low_target
.get_pc
) (regcache
);
2206 fprintf (stderr
, " resuming from pc 0x%lx\n", (long) pc
);
2209 /* If we have pending signals, consume one unless we are trying to reinsert
2211 if (lwp
->pending_signals
!= NULL
&& lwp
->bp_reinsert
== 0)
2213 struct pending_signals
**p_sig
;
2215 p_sig
= &lwp
->pending_signals
;
2216 while ((*p_sig
)->prev
!= NULL
)
2217 p_sig
= &(*p_sig
)->prev
;
2219 signal
= (*p_sig
)->signal
;
2220 if ((*p_sig
)->info
.si_signo
!= 0)
2221 ptrace (PTRACE_SETSIGINFO
, lwpid_of (lwp
), 0, &(*p_sig
)->info
);
2227 if (the_low_target
.prepare_to_resume
!= NULL
)
2228 the_low_target
.prepare_to_resume (lwp
);
2230 regcache_invalidate_one ((struct inferior_list_entry
*)
2231 get_lwp_thread (lwp
));
2234 lwp
->stopped_by_watchpoint
= 0;
2235 lwp
->stepping
= step
;
2236 ptrace (step
? PTRACE_SINGLESTEP
: PTRACE_CONT
, lwpid_of (lwp
), 0,
2237 /* Coerce to a uintptr_t first to avoid potential gcc warning
2238 of coercing an 8 byte integer to a 4 byte pointer. */
2239 (PTRACE_ARG4_TYPE
) (uintptr_t) signal
);
2241 current_inferior
= saved_inferior
;
2244 /* ESRCH from ptrace either means that the thread was already
2245 running (an error) or that it is gone (a race condition). If
2246 it's gone, we will get a notification the next time we wait,
2247 so we can ignore the error. We could differentiate these
2248 two, but it's tricky without waiting; the thread still exists
2249 as a zombie, so sending it signal 0 would succeed. So just
2254 perror_with_name ("ptrace");
2258 struct thread_resume_array
2260 struct thread_resume
*resume
;
2264 /* This function is called once per thread. We look up the thread
2265 in RESUME_PTR, and mark the thread with a pointer to the appropriate
2268 This algorithm is O(threads * resume elements), but resume elements
2269 is small (and will remain small at least until GDB supports thread
2272 linux_set_resume_request (struct inferior_list_entry
*entry
, void *arg
)
2274 struct lwp_info
*lwp
;
2275 struct thread_info
*thread
;
2277 struct thread_resume_array
*r
;
2279 thread
= (struct thread_info
*) entry
;
2280 lwp
= get_thread_lwp (thread
);
2283 for (ndx
= 0; ndx
< r
->n
; ndx
++)
2285 ptid_t ptid
= r
->resume
[ndx
].thread
;
2286 if (ptid_equal (ptid
, minus_one_ptid
)
2287 || ptid_equal (ptid
, entry
->id
)
2288 || (ptid_is_pid (ptid
)
2289 && (ptid_get_pid (ptid
) == pid_of (lwp
)))
2290 || (ptid_get_lwp (ptid
) == -1
2291 && (ptid_get_pid (ptid
) == pid_of (lwp
))))
2293 if (r
->resume
[ndx
].kind
== resume_stop
2294 && lwp
->last_resume_kind
== resume_stop
)
2297 fprintf (stderr
, "already %s LWP %ld at GDB's request\n",
2298 thread
->last_status
.kind
== TARGET_WAITKIND_STOPPED
2306 lwp
->resume
= &r
->resume
[ndx
];
2307 lwp
->last_resume_kind
= lwp
->resume
->kind
;
2312 /* No resume action for this thread. */
2319 /* Set *FLAG_P if this lwp has an interesting status pending. */
2321 resume_status_pending_p (struct inferior_list_entry
*entry
, void *flag_p
)
2323 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2325 /* LWPs which will not be resumed are not interesting, because
2326 we might not wait for them next time through linux_wait. */
2327 if (lwp
->resume
== NULL
)
2330 if (lwp
->status_pending_p
)
2331 * (int *) flag_p
= 1;
2336 /* Return 1 if this lwp that GDB wants running is stopped at an
2337 internal breakpoint that we need to step over. It assumes that any
2338 required STOP_PC adjustment has already been propagated to the
2339 inferior's regcache. */
2342 need_step_over_p (struct inferior_list_entry
*entry
, void *dummy
)
2344 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2345 struct thread_info
*saved_inferior
;
2348 /* LWPs which will not be resumed are not interesting, because we
2349 might not wait for them next time through linux_wait. */
2355 "Need step over [LWP %ld]? Ignoring, not stopped\n",
2360 if (lwp
->last_resume_kind
== resume_stop
)
2364 "Need step over [LWP %ld]? Ignoring, should remain stopped\n",
2369 if (!lwp
->need_step_over
)
2373 "Need step over [LWP %ld]? No\n", lwpid_of (lwp
));
2376 if (lwp
->status_pending_p
)
2380 "Need step over [LWP %ld]? Ignoring, has pending status.\n",
2385 /* Note: PC, not STOP_PC. Either GDB has adjusted the PC already,
2389 /* If the PC has changed since we stopped, then don't do anything,
2390 and let the breakpoint/tracepoint be hit. This happens if, for
2391 instance, GDB handled the decr_pc_after_break subtraction itself,
2392 GDB is OOL stepping this thread, or the user has issued a "jump"
2393 command, or poked thread's registers herself. */
2394 if (pc
!= lwp
->stop_pc
)
2398 "Need step over [LWP %ld]? Cancelling, PC was changed. "
2399 "Old stop_pc was 0x%s, PC is now 0x%s\n",
2400 lwpid_of (lwp
), paddress (lwp
->stop_pc
), paddress (pc
));
2402 lwp
->need_step_over
= 0;
2406 saved_inferior
= current_inferior
;
2407 current_inferior
= get_lwp_thread (lwp
);
2409 /* We can only step over breakpoints we know about. */
2410 if (breakpoint_here (pc
))
2412 /* Don't step over a breakpoint that GDB expects to hit
2414 if (gdb_breakpoint_here (pc
))
2418 "Need step over [LWP %ld]? yes, but found"
2419 " GDB breakpoint at 0x%s; skipping step over\n",
2420 lwpid_of (lwp
), paddress (pc
));
2422 current_inferior
= saved_inferior
;
2429 "Need step over [LWP %ld]? yes, found breakpoint at 0x%s\n",
2430 lwpid_of (lwp
), paddress (pc
));
2432 /* We've found an lwp that needs stepping over --- return 1 so
2433 that find_inferior stops looking. */
2434 current_inferior
= saved_inferior
;
2436 /* If the step over is cancelled, this is set again. */
2437 lwp
->need_step_over
= 0;
2442 current_inferior
= saved_inferior
;
2446 "Need step over [LWP %ld]? No, no breakpoint found at 0x%s\n",
2447 lwpid_of (lwp
), paddress (pc
));
2452 /* Start a step-over operation on LWP. When LWP stopped at a
2453 breakpoint, to make progress, we need to remove the breakpoint out
2454 of the way. If we let other threads run while we do that, they may
2455 pass by the breakpoint location and miss hitting it. To avoid
2456 that, a step-over momentarily stops all threads while LWP is
2457 single-stepped while the breakpoint is temporarily uninserted from
2458 the inferior. When the single-step finishes, we reinsert the
2459 breakpoint, and let all threads that are supposed to be running,
2462 On targets that don't support hardware single-step, we don't
2463 currently support full software single-stepping. Instead, we only
2464 support stepping over the thread event breakpoint, by asking the
2465 low target where to place a reinsert breakpoint. Since this
2466 routine assumes the breakpoint being stepped over is a thread event
2467 breakpoint, it usually assumes the return address of the current
2468 function is a good enough place to set the reinsert breakpoint. */
2471 start_step_over (struct lwp_info
*lwp
)
2473 struct thread_info
*saved_inferior
;
2479 "Starting step-over on LWP %ld. Stopping all threads\n",
2485 fprintf (stderr
, "Done stopping all threads for step-over.\n");
2487 /* Note, we should always reach here with an already adjusted PC,
2488 either by GDB (if we're resuming due to GDB's request), or by our
2489 caller, if we just finished handling an internal breakpoint GDB
2490 shouldn't care about. */
2493 saved_inferior
= current_inferior
;
2494 current_inferior
= get_lwp_thread (lwp
);
2496 lwp
->bp_reinsert
= pc
;
2497 uninsert_breakpoints_at (pc
);
2499 if (can_hardware_single_step ())
2505 CORE_ADDR raddr
= (*the_low_target
.breakpoint_reinsert_addr
) ();
2506 set_reinsert_breakpoint (raddr
);
2510 current_inferior
= saved_inferior
;
2512 linux_resume_one_lwp (lwp
, step
, 0, NULL
);
2514 /* Require next event from this LWP. */
2515 step_over_bkpt
= lwp
->head
.id
;
2519 /* Finish a step-over. Reinsert the breakpoint we had uninserted in
2520 start_step_over, if still there, and delete any reinsert
2521 breakpoints we've set, on non hardware single-step targets. */
2524 finish_step_over (struct lwp_info
*lwp
)
2526 if (lwp
->bp_reinsert
!= 0)
2529 fprintf (stderr
, "Finished step over.\n");
2531 /* Reinsert any breakpoint at LWP->BP_REINSERT. Note that there
2532 may be no breakpoint to reinsert there by now. */
2533 reinsert_breakpoints_at (lwp
->bp_reinsert
);
2535 lwp
->bp_reinsert
= 0;
2537 /* Delete any software-single-step reinsert breakpoints. No
2538 longer needed. We don't have to worry about other threads
2539 hitting this trap, and later not being able to explain it,
2540 because we were stepping over a breakpoint, and we hold all
2541 threads but LWP stopped while doing that. */
2542 if (!can_hardware_single_step ())
2543 delete_reinsert_breakpoints ();
2545 step_over_bkpt
= null_ptid
;
2552 /* This function is called once per thread. We check the thread's resume
2553 request, which will tell us whether to resume, step, or leave the thread
2554 stopped; and what signal, if any, it should be sent.
2556 For threads which we aren't explicitly told otherwise, we preserve
2557 the stepping flag; this is used for stepping over gdbserver-placed
2560 If pending_flags was set in any thread, we queue any needed
2561 signals, since we won't actually resume. We already have a pending
2562 event to report, so we don't need to preserve any step requests;
2563 they should be re-issued if necessary. */
2566 linux_resume_one_thread (struct inferior_list_entry
*entry
, void *arg
)
2568 struct lwp_info
*lwp
;
2569 struct thread_info
*thread
;
2571 int leave_all_stopped
= * (int *) arg
;
2574 thread
= (struct thread_info
*) entry
;
2575 lwp
= get_thread_lwp (thread
);
2577 if (lwp
->resume
== NULL
)
2580 if (lwp
->resume
->kind
== resume_stop
)
2583 fprintf (stderr
, "resume_stop request for LWP %ld\n", lwpid_of (lwp
));
2588 fprintf (stderr
, "stopping LWP %ld\n", lwpid_of (lwp
));
2590 /* Stop the thread, and wait for the event asynchronously,
2591 through the event loop. */
2592 send_sigstop (&lwp
->head
);
2597 fprintf (stderr
, "already stopped LWP %ld\n",
2600 /* The LWP may have been stopped in an internal event that
2601 was not meant to be notified back to GDB (e.g., gdbserver
2602 breakpoint), so we should be reporting a stop event in
2605 /* If the thread already has a pending SIGSTOP, this is a
2606 no-op. Otherwise, something later will presumably resume
2607 the thread and this will cause it to cancel any pending
2608 operation, due to last_resume_kind == resume_stop. If
2609 the thread already has a pending status to report, we
2610 will still report it the next time we wait - see
2611 status_pending_p_callback. */
2612 send_sigstop (&lwp
->head
);
2615 /* For stop requests, we're done. */
2617 thread
->last_status
.kind
= TARGET_WAITKIND_IGNORE
;
2621 /* If this thread which is about to be resumed has a pending status,
2622 then don't resume any threads - we can just report the pending
2623 status. Make sure to queue any signals that would otherwise be
2624 sent. In all-stop mode, we do this decision based on if *any*
2625 thread has a pending status. If there's a thread that needs the
2626 step-over-breakpoint dance, then don't resume any other thread
2627 but that particular one. */
2628 leave_pending
= (lwp
->status_pending_p
|| leave_all_stopped
);
2633 fprintf (stderr
, "resuming LWP %ld\n", lwpid_of (lwp
));
2635 step
= (lwp
->resume
->kind
== resume_step
);
2636 linux_resume_one_lwp (lwp
, step
, lwp
->resume
->sig
, NULL
);
2641 fprintf (stderr
, "leaving LWP %ld stopped\n", lwpid_of (lwp
));
2643 /* If we have a new signal, enqueue the signal. */
2644 if (lwp
->resume
->sig
!= 0)
2646 struct pending_signals
*p_sig
;
2647 p_sig
= xmalloc (sizeof (*p_sig
));
2648 p_sig
->prev
= lwp
->pending_signals
;
2649 p_sig
->signal
= lwp
->resume
->sig
;
2650 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
2652 /* If this is the same signal we were previously stopped by,
2653 make sure to queue its siginfo. We can ignore the return
2654 value of ptrace; if it fails, we'll skip
2655 PTRACE_SETSIGINFO. */
2656 if (WIFSTOPPED (lwp
->last_status
)
2657 && WSTOPSIG (lwp
->last_status
) == lwp
->resume
->sig
)
2658 ptrace (PTRACE_GETSIGINFO
, lwpid_of (lwp
), 0, &p_sig
->info
);
2660 lwp
->pending_signals
= p_sig
;
2664 thread
->last_status
.kind
= TARGET_WAITKIND_IGNORE
;
2670 linux_resume (struct thread_resume
*resume_info
, size_t n
)
2672 struct thread_resume_array array
= { resume_info
, n
};
2673 struct lwp_info
*need_step_over
= NULL
;
2675 int leave_all_stopped
;
2677 find_inferior (&all_threads
, linux_set_resume_request
, &array
);
2679 /* If there is a thread which would otherwise be resumed, which has
2680 a pending status, then don't resume any threads - we can just
2681 report the pending status. Make sure to queue any signals that
2682 would otherwise be sent. In non-stop mode, we'll apply this
2683 logic to each thread individually. We consume all pending events
2684 before considering to start a step-over (in all-stop). */
2687 find_inferior (&all_lwps
, resume_status_pending_p
, &any_pending
);
2689 /* If there is a thread which would otherwise be resumed, which is
2690 stopped at a breakpoint that needs stepping over, then don't
2691 resume any threads - have it step over the breakpoint with all
2692 other threads stopped, then resume all threads again. Make sure
2693 to queue any signals that would otherwise be delivered or
2695 if (!any_pending
&& supports_breakpoints ())
2697 = (struct lwp_info
*) find_inferior (&all_lwps
,
2698 need_step_over_p
, NULL
);
2700 leave_all_stopped
= (need_step_over
!= NULL
|| any_pending
);
2704 if (need_step_over
!= NULL
)
2705 fprintf (stderr
, "Not resuming all, need step over\n");
2706 else if (any_pending
)
2708 "Not resuming, all-stop and found "
2709 "an LWP with pending status\n");
2711 fprintf (stderr
, "Resuming, no pending status or step over needed\n");
2714 /* Even if we're leaving threads stopped, queue all signals we'd
2715 otherwise deliver. */
2716 find_inferior (&all_threads
, linux_resume_one_thread
, &leave_all_stopped
);
2719 start_step_over (need_step_over
);
2722 /* This function is called once per thread. We check the thread's
2723 last resume request, which will tell us whether to resume, step, or
2724 leave the thread stopped. Any signal the client requested to be
2725 delivered has already been enqueued at this point.
2727 If any thread that GDB wants running is stopped at an internal
2728 breakpoint that needs stepping over, we start a step-over operation
2729 on that particular thread, and leave all others stopped. */
2732 proceed_one_lwp (struct inferior_list_entry
*entry
)
2734 struct lwp_info
*lwp
;
2737 lwp
= (struct lwp_info
*) entry
;
2741 "proceed_one_lwp: lwp %ld\n", lwpid_of (lwp
));
2746 fprintf (stderr
, " LWP %ld already running\n", lwpid_of (lwp
));
2750 if (lwp
->last_resume_kind
== resume_stop
)
2753 fprintf (stderr
, " client wants LWP %ld stopped\n", lwpid_of (lwp
));
2757 if (lwp
->status_pending_p
)
2760 fprintf (stderr
, " LWP %ld has pending status, leaving stopped\n",
2768 fprintf (stderr
, " LWP %ld is suspended\n", lwpid_of (lwp
));
2772 step
= lwp
->last_resume_kind
== resume_step
;
2773 linux_resume_one_lwp (lwp
, step
, 0, NULL
);
2776 /* When we finish a step-over, set threads running again. If there's
2777 another thread that may need a step-over, now's the time to start
2778 it. Eventually, we'll move all threads past their breakpoints. */
2781 proceed_all_lwps (void)
2783 struct lwp_info
*need_step_over
;
2785 /* If there is a thread which would otherwise be resumed, which is
2786 stopped at a breakpoint that needs stepping over, then don't
2787 resume any threads - have it step over the breakpoint with all
2788 other threads stopped, then resume all threads again. */
2790 if (supports_breakpoints ())
2793 = (struct lwp_info
*) find_inferior (&all_lwps
,
2794 need_step_over_p
, NULL
);
2796 if (need_step_over
!= NULL
)
2799 fprintf (stderr
, "proceed_all_lwps: found "
2800 "thread %ld needing a step-over\n",
2801 lwpid_of (need_step_over
));
2803 start_step_over (need_step_over
);
2809 fprintf (stderr
, "Proceeding, no step-over needed\n");
2811 for_each_inferior (&all_lwps
, proceed_one_lwp
);
2814 /* Stopped LWPs that the client wanted to be running, that don't have
2815 pending statuses, are set to run again, except for EXCEPT, if not
2816 NULL. This undoes a stop_all_lwps call. */
2819 unstop_all_lwps (struct lwp_info
*except
)
2825 "unstopping all lwps, except=(LWP %ld)\n", lwpid_of (except
));
2828 "unstopping all lwps\n");
2831 /* Make sure proceed_one_lwp doesn't try to resume this thread. */
2833 ++except
->suspended
;
2835 for_each_inferior (&all_lwps
, proceed_one_lwp
);
2838 --except
->suspended
;
2841 #ifdef HAVE_LINUX_USRREGS
2844 register_addr (int regnum
)
2848 if (regnum
< 0 || regnum
>= the_low_target
.num_regs
)
2849 error ("Invalid register number %d.", regnum
);
2851 addr
= the_low_target
.regmap
[regnum
];
2856 /* Fetch one register. */
2858 fetch_register (struct regcache
*regcache
, int regno
)
2865 if (regno
>= the_low_target
.num_regs
)
2867 if ((*the_low_target
.cannot_fetch_register
) (regno
))
2870 regaddr
= register_addr (regno
);
2874 pid
= lwpid_of (get_thread_lwp (current_inferior
));
2875 size
= ((register_size (regno
) + sizeof (PTRACE_XFER_TYPE
) - 1)
2876 & - sizeof (PTRACE_XFER_TYPE
));
2877 buf
= alloca (size
);
2878 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
2881 *(PTRACE_XFER_TYPE
*) (buf
+ i
) =
2882 ptrace (PTRACE_PEEKUSER
, pid
,
2883 /* Coerce to a uintptr_t first to avoid potential gcc warning
2884 of coercing an 8 byte integer to a 4 byte pointer. */
2885 (PTRACE_ARG3_TYPE
) (uintptr_t) regaddr
, 0);
2886 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
2888 error ("reading register %d: %s", regno
, strerror (errno
));
2891 if (the_low_target
.supply_ptrace_register
)
2892 the_low_target
.supply_ptrace_register (regcache
, regno
, buf
);
2894 supply_register (regcache
, regno
, buf
);
2897 /* Fetch all registers, or just one, from the child process. */
2899 usr_fetch_inferior_registers (struct regcache
*regcache
, int regno
)
2902 for (regno
= 0; regno
< the_low_target
.num_regs
; regno
++)
2903 fetch_register (regcache
, regno
);
2905 fetch_register (regcache
, regno
);
2908 /* Store our register values back into the inferior.
2909 If REGNO is -1, do this for all registers.
2910 Otherwise, REGNO specifies which register (so we can save time). */
2912 usr_store_inferior_registers (struct regcache
*regcache
, int regno
)
2921 if (regno
>= the_low_target
.num_regs
)
2924 if ((*the_low_target
.cannot_store_register
) (regno
) == 1)
2927 regaddr
= register_addr (regno
);
2931 size
= (register_size (regno
) + sizeof (PTRACE_XFER_TYPE
) - 1)
2932 & - sizeof (PTRACE_XFER_TYPE
);
2933 buf
= alloca (size
);
2934 memset (buf
, 0, size
);
2936 if (the_low_target
.collect_ptrace_register
)
2937 the_low_target
.collect_ptrace_register (regcache
, regno
, buf
);
2939 collect_register (regcache
, regno
, buf
);
2941 pid
= lwpid_of (get_thread_lwp (current_inferior
));
2942 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
2945 ptrace (PTRACE_POKEUSER
, pid
,
2946 /* Coerce to a uintptr_t first to avoid potential gcc warning
2947 about coercing an 8 byte integer to a 4 byte pointer. */
2948 (PTRACE_ARG3_TYPE
) (uintptr_t) regaddr
,
2949 (PTRACE_ARG4_TYPE
) *(PTRACE_XFER_TYPE
*) (buf
+ i
));
2952 /* At this point, ESRCH should mean the process is
2953 already gone, in which case we simply ignore attempts
2954 to change its registers. See also the related
2955 comment in linux_resume_one_lwp. */
2959 if ((*the_low_target
.cannot_store_register
) (regno
) == 0)
2960 error ("writing register %d: %s", regno
, strerror (errno
));
2962 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
2966 for (regno
= 0; regno
< the_low_target
.num_regs
; regno
++)
2967 usr_store_inferior_registers (regcache
, regno
);
2969 #endif /* HAVE_LINUX_USRREGS */
2973 #ifdef HAVE_LINUX_REGSETS
2976 regsets_fetch_inferior_registers (struct regcache
*regcache
)
2978 struct regset_info
*regset
;
2979 int saw_general_regs
= 0;
2983 regset
= target_regsets
;
2985 pid
= lwpid_of (get_thread_lwp (current_inferior
));
2986 while (regset
->size
>= 0)
2991 if (regset
->size
== 0 || disabled_regsets
[regset
- target_regsets
])
2997 buf
= xmalloc (regset
->size
);
2999 nt_type
= regset
->nt_type
;
3003 iov
.iov_len
= regset
->size
;
3004 data
= (void *) &iov
;
3010 res
= ptrace (regset
->get_request
, pid
, nt_type
, data
);
3012 res
= ptrace (regset
->get_request
, pid
, data
, nt_type
);
3018 /* If we get EIO on a regset, do not try it again for
3020 disabled_regsets
[regset
- target_regsets
] = 1;
3027 sprintf (s
, "ptrace(regsets_fetch_inferior_registers) PID=%d",
3032 else if (regset
->type
== GENERAL_REGS
)
3033 saw_general_regs
= 1;
3034 regset
->store_function (regcache
, buf
);
3038 if (saw_general_regs
)
3045 regsets_store_inferior_registers (struct regcache
*regcache
)
3047 struct regset_info
*regset
;
3048 int saw_general_regs
= 0;
3052 regset
= target_regsets
;
3054 pid
= lwpid_of (get_thread_lwp (current_inferior
));
3055 while (regset
->size
>= 0)
3060 if (regset
->size
== 0 || disabled_regsets
[regset
- target_regsets
])
3066 buf
= xmalloc (regset
->size
);
3068 /* First fill the buffer with the current register set contents,
3069 in case there are any items in the kernel's regset that are
3070 not in gdbserver's regcache. */
3072 nt_type
= regset
->nt_type
;
3076 iov
.iov_len
= regset
->size
;
3077 data
= (void *) &iov
;
3083 res
= ptrace (regset
->get_request
, pid
, nt_type
, data
);
3085 res
= ptrace (regset
->get_request
, pid
, &iov
, data
);
3090 /* Then overlay our cached registers on that. */
3091 regset
->fill_function (regcache
, buf
);
3093 /* Only now do we write the register set. */
3095 res
= ptrace (regset
->set_request
, pid
, nt_type
, data
);
3097 res
= ptrace (regset
->set_request
, pid
, data
, nt_type
);
3105 /* If we get EIO on a regset, do not try it again for
3107 disabled_regsets
[regset
- target_regsets
] = 1;
3111 else if (errno
== ESRCH
)
3113 /* At this point, ESRCH should mean the process is
3114 already gone, in which case we simply ignore attempts
3115 to change its registers. See also the related
3116 comment in linux_resume_one_lwp. */
3122 perror ("Warning: ptrace(regsets_store_inferior_registers)");
3125 else if (regset
->type
== GENERAL_REGS
)
3126 saw_general_regs
= 1;
3130 if (saw_general_regs
)
3137 #endif /* HAVE_LINUX_REGSETS */
3141 linux_fetch_registers (struct regcache
*regcache
, int regno
)
3143 #ifdef HAVE_LINUX_REGSETS
3144 if (regsets_fetch_inferior_registers (regcache
) == 0)
3147 #ifdef HAVE_LINUX_USRREGS
3148 usr_fetch_inferior_registers (regcache
, regno
);
3153 linux_store_registers (struct regcache
*regcache
, int regno
)
3155 #ifdef HAVE_LINUX_REGSETS
3156 if (regsets_store_inferior_registers (regcache
) == 0)
3159 #ifdef HAVE_LINUX_USRREGS
3160 usr_store_inferior_registers (regcache
, regno
);
3165 /* Copy LEN bytes from inferior's memory starting at MEMADDR
3166 to debugger memory starting at MYADDR. */
3169 linux_read_memory (CORE_ADDR memaddr
, unsigned char *myaddr
, int len
)
3172 /* Round starting address down to longword boundary. */
3173 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
3174 /* Round ending address up; get number of longwords that makes. */
3176 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1)
3177 / sizeof (PTRACE_XFER_TYPE
);
3178 /* Allocate buffer of that many longwords. */
3179 register PTRACE_XFER_TYPE
*buffer
3180 = (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
3183 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
3185 /* Try using /proc. Don't bother for one word. */
3186 if (len
>= 3 * sizeof (long))
3188 /* We could keep this file open and cache it - possibly one per
3189 thread. That requires some juggling, but is even faster. */
3190 sprintf (filename
, "/proc/%d/mem", pid
);
3191 fd
= open (filename
, O_RDONLY
| O_LARGEFILE
);
3195 /* If pread64 is available, use it. It's faster if the kernel
3196 supports it (only one syscall), and it's 64-bit safe even on
3197 32-bit platforms (for instance, SPARC debugging a SPARC64
3200 if (pread64 (fd
, myaddr
, len
, memaddr
) != len
)
3202 if (lseek (fd
, memaddr
, SEEK_SET
) == -1 || read (fd
, myaddr
, len
) != len
)
3214 /* Read all the longwords */
3215 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
3218 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
3219 about coercing an 8 byte integer to a 4 byte pointer. */
3220 buffer
[i
] = ptrace (PTRACE_PEEKTEXT
, pid
,
3221 (PTRACE_ARG3_TYPE
) (uintptr_t) addr
, 0);
3226 /* Copy appropriate bytes out of the buffer. */
3228 (char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)),
3234 /* Copy LEN bytes of data from debugger memory at MYADDR to inferior's
3235 memory at MEMADDR. On failure (cannot write to the inferior)
3236 returns the value of errno. */
3239 linux_write_memory (CORE_ADDR memaddr
, const unsigned char *myaddr
, int len
)
3242 /* Round starting address down to longword boundary. */
3243 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
3244 /* Round ending address up; get number of longwords that makes. */
3246 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1) / sizeof (PTRACE_XFER_TYPE
);
3247 /* Allocate buffer of that many longwords. */
3248 register PTRACE_XFER_TYPE
*buffer
= (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
3249 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
3253 /* Dump up to four bytes. */
3254 unsigned int val
= * (unsigned int *) myaddr
;
3260 val
= val
& 0xffffff;
3261 fprintf (stderr
, "Writing %0*x to 0x%08lx\n", 2 * ((len
< 4) ? len
: 4),
3262 val
, (long)memaddr
);
3265 /* Fill start and end extra bytes of buffer with existing memory data. */
3268 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
3269 about coercing an 8 byte integer to a 4 byte pointer. */
3270 buffer
[0] = ptrace (PTRACE_PEEKTEXT
, pid
,
3271 (PTRACE_ARG3_TYPE
) (uintptr_t) addr
, 0);
3279 = ptrace (PTRACE_PEEKTEXT
, pid
,
3280 /* Coerce to a uintptr_t first to avoid potential gcc warning
3281 about coercing an 8 byte integer to a 4 byte pointer. */
3282 (PTRACE_ARG3_TYPE
) (uintptr_t) (addr
+ (count
- 1)
3283 * sizeof (PTRACE_XFER_TYPE
)),
3289 /* Copy data to be written over corresponding part of buffer. */
3291 memcpy ((char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)), myaddr
, len
);
3293 /* Write the entire buffer. */
3295 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
3298 ptrace (PTRACE_POKETEXT
, pid
,
3299 /* Coerce to a uintptr_t first to avoid potential gcc warning
3300 about coercing an 8 byte integer to a 4 byte pointer. */
3301 (PTRACE_ARG3_TYPE
) (uintptr_t) addr
,
3302 (PTRACE_ARG4_TYPE
) buffer
[i
]);
3310 /* Non-zero if the kernel supports PTRACE_O_TRACEFORK. */
3311 static int linux_supports_tracefork_flag
;
3313 /* Helper functions for linux_test_for_tracefork, called via clone (). */
3316 linux_tracefork_grandchild (void *arg
)
3321 #define STACK_SIZE 4096
3324 linux_tracefork_child (void *arg
)
3326 ptrace (PTRACE_TRACEME
, 0, 0, 0);
3327 kill (getpid (), SIGSTOP
);
3329 #if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
3332 linux_tracefork_grandchild (NULL
);
3334 #else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
3337 __clone2 (linux_tracefork_grandchild
, arg
, STACK_SIZE
,
3338 CLONE_VM
| SIGCHLD
, NULL
);
3340 clone (linux_tracefork_grandchild
, arg
+ STACK_SIZE
,
3341 CLONE_VM
| SIGCHLD
, NULL
);
3344 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
3349 /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. Make
3350 sure that we can enable the option, and that it had the desired
3354 linux_test_for_tracefork (void)
3356 int child_pid
, ret
, status
;
3358 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
3359 char *stack
= xmalloc (STACK_SIZE
* 4);
3360 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
3362 linux_supports_tracefork_flag
= 0;
3364 #if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
3366 child_pid
= fork ();
3368 linux_tracefork_child (NULL
);
3370 #else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
3372 /* Use CLONE_VM instead of fork, to support uClinux (no MMU). */
3374 child_pid
= __clone2 (linux_tracefork_child
, stack
, STACK_SIZE
,
3375 CLONE_VM
| SIGCHLD
, stack
+ STACK_SIZE
* 2);
3376 #else /* !__ia64__ */
3377 child_pid
= clone (linux_tracefork_child
, stack
+ STACK_SIZE
,
3378 CLONE_VM
| SIGCHLD
, stack
+ STACK_SIZE
* 2);
3379 #endif /* !__ia64__ */
3381 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
3383 if (child_pid
== -1)
3384 perror_with_name ("clone");
3386 ret
= my_waitpid (child_pid
, &status
, 0);
3388 perror_with_name ("waitpid");
3389 else if (ret
!= child_pid
)
3390 error ("linux_test_for_tracefork: waitpid: unexpected result %d.", ret
);
3391 if (! WIFSTOPPED (status
))
3392 error ("linux_test_for_tracefork: waitpid: unexpected status %d.", status
);
3394 ret
= ptrace (PTRACE_SETOPTIONS
, child_pid
, 0,
3395 (PTRACE_ARG4_TYPE
) PTRACE_O_TRACEFORK
);
3398 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
3401 warning ("linux_test_for_tracefork: failed to kill child");
3405 ret
= my_waitpid (child_pid
, &status
, 0);
3406 if (ret
!= child_pid
)
3407 warning ("linux_test_for_tracefork: failed to wait for killed child");
3408 else if (!WIFSIGNALED (status
))
3409 warning ("linux_test_for_tracefork: unexpected wait status 0x%x from "
3410 "killed child", status
);
3415 ret
= ptrace (PTRACE_CONT
, child_pid
, 0, 0);
3417 warning ("linux_test_for_tracefork: failed to resume child");
3419 ret
= my_waitpid (child_pid
, &status
, 0);
3421 if (ret
== child_pid
&& WIFSTOPPED (status
)
3422 && status
>> 16 == PTRACE_EVENT_FORK
)
3425 ret
= ptrace (PTRACE_GETEVENTMSG
, child_pid
, 0, &second_pid
);
3426 if (ret
== 0 && second_pid
!= 0)
3430 linux_supports_tracefork_flag
= 1;
3431 my_waitpid (second_pid
, &second_status
, 0);
3432 ret
= ptrace (PTRACE_KILL
, second_pid
, 0, 0);
3434 warning ("linux_test_for_tracefork: failed to kill second child");
3435 my_waitpid (second_pid
, &status
, 0);
3439 warning ("linux_test_for_tracefork: unexpected result from waitpid "
3440 "(%d, status 0x%x)", ret
, status
);
3444 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
3446 warning ("linux_test_for_tracefork: failed to kill child");
3447 my_waitpid (child_pid
, &status
, 0);
3449 while (WIFSTOPPED (status
));
3451 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
3453 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
3458 linux_look_up_symbols (void)
3460 #ifdef USE_THREAD_DB
3461 struct process_info
*proc
= current_process ();
3463 if (proc
->private->thread_db
!= NULL
)
3466 /* If the kernel supports tracing forks then it also supports tracing
3467 clones, and then we don't need to use the magic thread event breakpoint
3468 to learn about threads. */
3469 thread_db_init (!linux_supports_tracefork_flag
);
3474 linux_request_interrupt (void)
3476 extern unsigned long signal_pid
;
3478 if (!ptid_equal (cont_thread
, null_ptid
)
3479 && !ptid_equal (cont_thread
, minus_one_ptid
))
3481 struct lwp_info
*lwp
;
3484 lwp
= get_thread_lwp (current_inferior
);
3485 lwpid
= lwpid_of (lwp
);
3486 kill_lwp (lwpid
, SIGINT
);
3489 kill_lwp (signal_pid
, SIGINT
);
3492 /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
3493 to debugger memory starting at MYADDR. */
3496 linux_read_auxv (CORE_ADDR offset
, unsigned char *myaddr
, unsigned int len
)
3498 char filename
[PATH_MAX
];
3500 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
3502 snprintf (filename
, sizeof filename
, "/proc/%d/auxv", pid
);
3504 fd
= open (filename
, O_RDONLY
);
3508 if (offset
!= (CORE_ADDR
) 0
3509 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
3512 n
= read (fd
, myaddr
, len
);
3519 /* These breakpoint and watchpoint related wrapper functions simply
3520 pass on the function call if the target has registered a
3521 corresponding function. */
3524 linux_insert_point (char type
, CORE_ADDR addr
, int len
)
3526 if (the_low_target
.insert_point
!= NULL
)
3527 return the_low_target
.insert_point (type
, addr
, len
);
3529 /* Unsupported (see target.h). */
3534 linux_remove_point (char type
, CORE_ADDR addr
, int len
)
3536 if (the_low_target
.remove_point
!= NULL
)
3537 return the_low_target
.remove_point (type
, addr
, len
);
3539 /* Unsupported (see target.h). */
3544 linux_stopped_by_watchpoint (void)
3546 struct lwp_info
*lwp
= get_thread_lwp (current_inferior
);
3548 return lwp
->stopped_by_watchpoint
;
3552 linux_stopped_data_address (void)
3554 struct lwp_info
*lwp
= get_thread_lwp (current_inferior
);
3556 return lwp
->stopped_data_address
;
3559 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
3560 #if defined(__mcoldfire__)
3561 /* These should really be defined in the kernel's ptrace.h header. */
3562 #define PT_TEXT_ADDR 49*4
3563 #define PT_DATA_ADDR 50*4
3564 #define PT_TEXT_END_ADDR 51*4
3567 /* Under uClinux, programs are loaded at non-zero offsets, which we need
3568 to tell gdb about. */
3571 linux_read_offsets (CORE_ADDR
*text_p
, CORE_ADDR
*data_p
)
3573 #if defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) && defined(PT_TEXT_END_ADDR)
3574 unsigned long text
, text_end
, data
;
3575 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
3579 text
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_TEXT_ADDR
, 0);
3580 text_end
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_TEXT_END_ADDR
, 0);
3581 data
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_DATA_ADDR
, 0);
3585 /* Both text and data offsets produced at compile-time (and so
3586 used by gdb) are relative to the beginning of the program,
3587 with the data segment immediately following the text segment.
3588 However, the actual runtime layout in memory may put the data
3589 somewhere else, so when we send gdb a data base-address, we
3590 use the real data base address and subtract the compile-time
3591 data base-address from it (which is just the length of the
3592 text segment). BSS immediately follows data in both
3595 *data_p
= data
- (text_end
- text
);
3605 compare_ints (const void *xa
, const void *xb
)
3607 int a
= *(const int *)xa
;
3608 int b
= *(const int *)xb
;
3614 unique (int *b
, int *e
)
3623 /* Given PID, iterates over all threads in that process.
3625 Information about each thread, in a format suitable for qXfer:osdata:thread
3626 is printed to BUFFER, if it's not NULL. BUFFER is assumed to be already
3627 initialized, and the caller is responsible for finishing and appending '\0'
3630 The list of cores that threads are running on is assigned to *CORES, if it
3631 is not NULL. If no cores are found, *CORES will be set to NULL. Caller
3632 should free *CORES. */
3635 list_threads (int pid
, struct buffer
*buffer
, char **cores
)
3639 int *core_numbers
= xmalloc (sizeof (int) * allocated
);
3643 struct stat statbuf
;
3645 sprintf (pathname
, "/proc/%d/task", pid
);
3646 if (stat (pathname
, &statbuf
) == 0 && S_ISDIR (statbuf
.st_mode
))
3648 dir
= opendir (pathname
);
3651 free (core_numbers
);
3655 while ((dp
= readdir (dir
)) != NULL
)
3657 unsigned long lwp
= strtoul (dp
->d_name
, NULL
, 10);
3661 unsigned core
= linux_core_of_thread (ptid_build (pid
, lwp
, 0));
3665 char s
[sizeof ("4294967295")];
3666 sprintf (s
, "%u", core
);
3668 if (count
== allocated
)
3671 core_numbers
= realloc (core_numbers
,
3672 sizeof (int) * allocated
);
3674 core_numbers
[count
++] = core
;
3676 buffer_xml_printf (buffer
,
3678 "<column name=\"pid\">%d</column>"
3679 "<column name=\"tid\">%s</column>"
3680 "<column name=\"core\">%s</column>"
3681 "</item>", pid
, dp
->d_name
, s
);
3686 buffer_xml_printf (buffer
,
3688 "<column name=\"pid\">%d</column>"
3689 "<column name=\"tid\">%s</column>"
3690 "</item>", pid
, dp
->d_name
);
3701 struct buffer buffer2
;
3704 qsort (core_numbers
, count
, sizeof (int), compare_ints
);
3706 /* Remove duplicates. */
3708 e
= unique (b
, core_numbers
+ count
);
3710 buffer_init (&buffer2
);
3712 for (b
= core_numbers
; b
!= e
; ++b
)
3714 char number
[sizeof ("4294967295")];
3715 sprintf (number
, "%u", *b
);
3716 buffer_xml_printf (&buffer2
, "%s%s",
3717 (b
== core_numbers
) ? "" : ",", number
);
3719 buffer_grow_str0 (&buffer2
, "");
3721 *cores
= buffer_finish (&buffer2
);
3724 free (core_numbers
);
3728 show_process (int pid
, const char *username
, struct buffer
*buffer
)
3732 char cmd
[MAXPATHLEN
+ 1];
3734 sprintf (pathname
, "/proc/%d/cmdline", pid
);
3736 if ((f
= fopen (pathname
, "r")) != NULL
)
3738 size_t len
= fread (cmd
, 1, sizeof (cmd
) - 1, f
);
3743 for (i
= 0; i
< len
; i
++)
3748 buffer_xml_printf (buffer
,
3750 "<column name=\"pid\">%d</column>"
3751 "<column name=\"user\">%s</column>"
3752 "<column name=\"command\">%s</column>",
3757 /* This only collects core numbers, and does not print threads. */
3758 list_threads (pid
, NULL
, &cores
);
3762 buffer_xml_printf (buffer
,
3763 "<column name=\"cores\">%s</column>", cores
);
3767 buffer_xml_printf (buffer
, "</item>");
3774 linux_qxfer_osdata (const char *annex
,
3775 unsigned char *readbuf
, unsigned const char *writebuf
,
3776 CORE_ADDR offset
, int len
)
3778 /* We make the process list snapshot when the object starts to be
3780 static const char *buf
;
3781 static long len_avail
= -1;
3782 static struct buffer buffer
;
3788 if (strcmp (annex
, "processes") == 0)
3790 else if (strcmp (annex
, "threads") == 0)
3795 if (!readbuf
|| writebuf
)
3800 if (len_avail
!= -1 && len_avail
!= 0)
3801 buffer_free (&buffer
);
3804 buffer_init (&buffer
);
3806 buffer_grow_str (&buffer
, "<osdata type=\"processes\">");
3808 buffer_grow_str (&buffer
, "<osdata type=\"threads\">");
3810 dirp
= opendir ("/proc");
3814 while ((dp
= readdir (dirp
)) != NULL
)
3816 struct stat statbuf
;
3817 char procentry
[sizeof ("/proc/4294967295")];
3819 if (!isdigit (dp
->d_name
[0])
3820 || strlen (dp
->d_name
) > sizeof ("4294967295") - 1)
3823 sprintf (procentry
, "/proc/%s", dp
->d_name
);
3824 if (stat (procentry
, &statbuf
) == 0
3825 && S_ISDIR (statbuf
.st_mode
))
3827 int pid
= (int) strtoul (dp
->d_name
, NULL
, 10);
3831 struct passwd
*entry
= getpwuid (statbuf
.st_uid
);
3832 show_process (pid
, entry
? entry
->pw_name
: "?", &buffer
);
3836 list_threads (pid
, &buffer
, NULL
);
3843 buffer_grow_str0 (&buffer
, "</osdata>\n");
3844 buf
= buffer_finish (&buffer
);
3845 len_avail
= strlen (buf
);
3848 if (offset
>= len_avail
)
3850 /* Done. Get rid of the data. */
3851 buffer_free (&buffer
);
3857 if (len
> len_avail
- offset
)
3858 len
= len_avail
- offset
;
3859 memcpy (readbuf
, buf
+ offset
, len
);
3864 /* Convert a native/host siginfo object, into/from the siginfo in the
3865 layout of the inferiors' architecture. */
3868 siginfo_fixup (struct siginfo
*siginfo
, void *inf_siginfo
, int direction
)
3872 if (the_low_target
.siginfo_fixup
!= NULL
)
3873 done
= the_low_target
.siginfo_fixup (siginfo
, inf_siginfo
, direction
);
3875 /* If there was no callback, or the callback didn't do anything,
3876 then just do a straight memcpy. */
3880 memcpy (siginfo
, inf_siginfo
, sizeof (struct siginfo
));
3882 memcpy (inf_siginfo
, siginfo
, sizeof (struct siginfo
));
3887 linux_xfer_siginfo (const char *annex
, unsigned char *readbuf
,
3888 unsigned const char *writebuf
, CORE_ADDR offset
, int len
)
3891 struct siginfo siginfo
;
3892 char inf_siginfo
[sizeof (struct siginfo
)];
3894 if (current_inferior
== NULL
)
3897 pid
= lwpid_of (get_thread_lwp (current_inferior
));
3900 fprintf (stderr
, "%s siginfo for lwp %d.\n",
3901 readbuf
!= NULL
? "Reading" : "Writing",
3904 if (offset
> sizeof (siginfo
))
3907 if (ptrace (PTRACE_GETSIGINFO
, pid
, 0, &siginfo
) != 0)
3910 /* When GDBSERVER is built as a 64-bit application, ptrace writes into
3911 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
3912 inferior with a 64-bit GDBSERVER should look the same as debugging it
3913 with a 32-bit GDBSERVER, we need to convert it. */
3914 siginfo_fixup (&siginfo
, inf_siginfo
, 0);
3916 if (offset
+ len
> sizeof (siginfo
))
3917 len
= sizeof (siginfo
) - offset
;
3919 if (readbuf
!= NULL
)
3920 memcpy (readbuf
, inf_siginfo
+ offset
, len
);
3923 memcpy (inf_siginfo
+ offset
, writebuf
, len
);
3925 /* Convert back to ptrace layout before flushing it out. */
3926 siginfo_fixup (&siginfo
, inf_siginfo
, 1);
3928 if (ptrace (PTRACE_SETSIGINFO
, pid
, 0, &siginfo
) != 0)
3935 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
3936 so we notice when children change state; as the handler for the
3937 sigsuspend in my_waitpid. */
3940 sigchld_handler (int signo
)
3942 int old_errno
= errno
;
3945 /* fprintf is not async-signal-safe, so call write directly. */
3946 write (2, "sigchld_handler\n", sizeof ("sigchld_handler\n") - 1);
3948 if (target_is_async_p ())
3949 async_file_mark (); /* trigger a linux_wait */
3955 linux_supports_non_stop (void)
3961 linux_async (int enable
)
3963 int previous
= (linux_event_pipe
[0] != -1);
3965 if (previous
!= enable
)
3968 sigemptyset (&mask
);
3969 sigaddset (&mask
, SIGCHLD
);
3971 sigprocmask (SIG_BLOCK
, &mask
, NULL
);
3975 if (pipe (linux_event_pipe
) == -1)
3976 fatal ("creating event pipe failed.");
3978 fcntl (linux_event_pipe
[0], F_SETFL
, O_NONBLOCK
);
3979 fcntl (linux_event_pipe
[1], F_SETFL
, O_NONBLOCK
);
3981 /* Register the event loop handler. */
3982 add_file_handler (linux_event_pipe
[0],
3983 handle_target_event
, NULL
);
3985 /* Always trigger a linux_wait. */
3990 delete_file_handler (linux_event_pipe
[0]);
3992 close (linux_event_pipe
[0]);
3993 close (linux_event_pipe
[1]);
3994 linux_event_pipe
[0] = -1;
3995 linux_event_pipe
[1] = -1;
3998 sigprocmask (SIG_UNBLOCK
, &mask
, NULL
);
4005 linux_start_non_stop (int nonstop
)
4007 /* Register or unregister from event-loop accordingly. */
4008 linux_async (nonstop
);
4013 linux_supports_multi_process (void)
4019 /* Enumerate spufs IDs for process PID. */
4021 spu_enumerate_spu_ids (long pid
, unsigned char *buf
, CORE_ADDR offset
, int len
)
4027 struct dirent
*entry
;
4029 sprintf (path
, "/proc/%ld/fd", pid
);
4030 dir
= opendir (path
);
4035 while ((entry
= readdir (dir
)) != NULL
)
4041 fd
= atoi (entry
->d_name
);
4045 sprintf (path
, "/proc/%ld/fd/%d", pid
, fd
);
4046 if (stat (path
, &st
) != 0)
4048 if (!S_ISDIR (st
.st_mode
))
4051 if (statfs (path
, &stfs
) != 0)
4053 if (stfs
.f_type
!= SPUFS_MAGIC
)
4056 if (pos
>= offset
&& pos
+ 4 <= offset
+ len
)
4058 *(unsigned int *)(buf
+ pos
- offset
) = fd
;
4068 /* Implements the to_xfer_partial interface for the TARGET_OBJECT_SPU
4069 object type, using the /proc file system. */
4071 linux_qxfer_spu (const char *annex
, unsigned char *readbuf
,
4072 unsigned const char *writebuf
,
4073 CORE_ADDR offset
, int len
)
4075 long pid
= lwpid_of (get_thread_lwp (current_inferior
));
4080 if (!writebuf
&& !readbuf
)
4088 return spu_enumerate_spu_ids (pid
, readbuf
, offset
, len
);
4091 sprintf (buf
, "/proc/%ld/fd/%s", pid
, annex
);
4092 fd
= open (buf
, writebuf
? O_WRONLY
: O_RDONLY
);
4097 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
4104 ret
= write (fd
, writebuf
, (size_t) len
);
4106 ret
= read (fd
, readbuf
, (size_t) len
);
4113 linux_core_of_thread (ptid_t ptid
)
4115 char filename
[sizeof ("/proc//task//stat")
4116 + 2 * 20 /* decimal digits for 2 numbers, max 2^64 bit each */
4119 char *content
= NULL
;
4122 int content_read
= 0;
4126 sprintf (filename
, "/proc/%d/task/%ld/stat",
4127 ptid_get_pid (ptid
), ptid_get_lwp (ptid
));
4128 f
= fopen (filename
, "r");
4135 content
= realloc (content
, content_read
+ 1024);
4136 n
= fread (content
+ content_read
, 1, 1024, f
);
4140 content
[content_read
] = '\0';
4145 p
= strchr (content
, '(');
4146 p
= strchr (p
, ')') + 2; /* skip ")" and a whitespace. */
4148 p
= strtok_r (p
, " ", &ts
);
4149 for (i
= 0; i
!= 36; ++i
)
4150 p
= strtok_r (NULL
, " ", &ts
);
4152 if (sscanf (p
, "%d", &core
) == 0)
4162 linux_process_qsupported (const char *query
)
4164 if (the_low_target
.process_qsupported
!= NULL
)
4165 the_low_target
.process_qsupported (query
);
4168 static struct target_ops linux_target_ops
= {
4169 linux_create_inferior
,
4177 linux_fetch_registers
,
4178 linux_store_registers
,
4181 linux_look_up_symbols
,
4182 linux_request_interrupt
,
4186 linux_stopped_by_watchpoint
,
4187 linux_stopped_data_address
,
4188 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
4193 #ifdef USE_THREAD_DB
4194 thread_db_get_tls_address
,
4199 hostio_last_error_from_errno
,
4202 linux_supports_non_stop
,
4204 linux_start_non_stop
,
4205 linux_supports_multi_process
,
4206 #ifdef USE_THREAD_DB
4207 thread_db_handle_monitor_command
,
4211 linux_core_of_thread
,
4212 linux_process_qsupported
4216 linux_init_signals ()
4218 /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
4219 to find what the cancel signal actually is. */
4220 #ifdef __SIGRTMIN /* Bionic doesn't use SIGRTMIN the way glibc does. */
4221 signal (__SIGRTMIN
+1, SIG_IGN
);
4226 initialize_low (void)
4228 struct sigaction sigchld_action
;
4229 memset (&sigchld_action
, 0, sizeof (sigchld_action
));
4230 set_target_ops (&linux_target_ops
);
4231 set_breakpoint_data (the_low_target
.breakpoint
,
4232 the_low_target
.breakpoint_len
);
4233 linux_init_signals ();
4234 linux_test_for_tracefork ();
4235 #ifdef HAVE_LINUX_REGSETS
4236 for (num_regsets
= 0; target_regsets
[num_regsets
].size
>= 0; num_regsets
++)
4238 disabled_regsets
= xmalloc (num_regsets
);
4241 sigchld_action
.sa_handler
= sigchld_handler
;
4242 sigemptyset (&sigchld_action
.sa_mask
);
4243 sigchld_action
.sa_flags
= SA_RESTART
;
4244 sigaction (SIGCHLD
, &sigchld_action
, NULL
);